Client keeps syncing when using S3

Nextcloud version (eg, 20.0.5): 24.0.4
Operating system and version (eg, Ubuntu 20.04): Arch
Apache or nginx version (eg, Apache 2.4.25): nginx …
PHP version (eg, 7.4):
External storage support 1.16.1

Backblaze B2 Bucket Settings:
Private: y
Default Encryption: y

External Storage Settings:
SSL: y
Encryption: y
Previews: y
Shares: y
Check for modifications: never

The issue you are facing:
The client keeps reuploading files over and over again when the synced folder is backed by a S3 Bucket.

Is this the first time you’ve seen this error? (Y/N): Y

Steps to replicate it:

  1. Add S3 Bucket from Backblaze B2 as external storage
  2. add external storage from step 1 as sync folder in client
  3. copy files into folder and let client sync
  4. client keeps uploading files over and over again(also notice in Backblaze file browser how file version counts keep increasing)

The output of your Nextcloud log in Admin > Logging:

Fehler	PHP	Error: Return type of Aws\Result::count() should either be compatible with Countable::count(): int, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/HasDataTrait.php#56	
2022-10-16T21:04:25+0200
Fehler	PHP	Error: Return type of Aws\Result::getIterator() should either be compatible with IteratorAggregate::getIterator(): Traversable, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/HasDataTrait.php#13	
2022-10-16T21:04:25+0200
Fehler	PHP	Error: Return type of Aws\Result::offsetUnset($offset) should either be compatible with ArrayAccess::offsetUnset(mixed $offset): void, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/HasDataTrait.php#46	
2022-10-16T21:04:25+0200
Fehler	PHP	Error: Return type of Aws\Result::offsetSet($offset, $value) should either be compatible with ArrayAccess::offsetSet(mixed $offset, mixed $value): void, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/HasDataTrait.php#36	
2022-10-16T21:04:25+0200
Fehler	PHP	Error: Return type of & Aws\Result::offsetGet($offset) should either be compatible with ArrayAccess::offsetGet(mixed $offset): mixed, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/HasDataTrait.php#26	
2022-10-16T21:04:25+0200
Fehler	PHP	Error: Return type of Aws\Result::offsetExists($offset) should either be compatible with ArrayAccess::offsetExists(mixed $offset): bool, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/HasDataTrait.php#41	
2022-10-16T21:04:25+0200
Fehler	PHP	Error: Aws\Credentials\Credentials implements the Serializable interface, which is deprecated. Implement __serialize() and __unserialize() instead (or in addition, if support for old PHP versions is necessary) at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/Credentials/Credentials.php#8	
2022-10-16T21:04:25+0200
Fehler	PHP	Error: Return type of Aws\Command::getIterator() should either be compatible with IteratorAggregate::getIterator(): Traversable, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/HasDataTrait.php#13	
2022-10-16T21:04:25+0200
Fehler	PHP	Error: Return type of Aws\Command::count() should either be compatible with Countable::count(): int, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/HasDataTrait.php#56	
2022-10-16T21:04:25+0200
Fehler	PHP	Error: Return type of Aws\Command::offsetUnset($offset) should either be compatible with ArrayAccess::offsetUnset(mixed $offset): void, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/HasDataTrait.php#46	
2022-10-16T21:04:25+0200
Fehler	PHP	Error: Return type of Aws\Command::offsetSet($offset, $value) should either be compatible with ArrayAccess::offsetSet(mixed $offset, mixed $value): void, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/HasDataTrait.php#36	
2022-10-16T21:04:25+0200
Fehler	PHP	Error: Return type of & Aws\Command::offsetGet($offset) should either be compatible with ArrayAccess::offsetGet(mixed $offset): mixed, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/HasDataTrait.php#26	
2022-10-16T21:04:25+0200
Fehler	PHP	Error: Return type of Aws\Command::offsetExists($offset) should either be compatible with ArrayAccess::offsetExists(mixed $offset): bool, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/HasDataTrait.php#41	
2022-10-16T21:04:25+0200
Fehler	PHP	Error: is_readable(): open_basedir restriction in effect. File(//.aws/config) is not within the allowed path(s): (/usr/share/webapps:/home/http/www/cloud.rfreyt.ag/data:/etc/webapps:/usr/lib/php:/var/lib/nextcloud:/var/log/nextcloud:/tmp) at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/Retry/ConfigurationProvider.php#158	
2022-10-16T21:04:25+0200
Fehler	PHP	Error: Return type of Aws\Endpoint\Partition::offsetUnset($offset) should either be compatible with ArrayAccess::offsetUnset(mixed $offset): void, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/HasDataTrait.php#46	
2022-10-16T21:04:25+0200
Fehler	PHP	Error: Return type of Aws\Endpoint\Partition::offsetSet($offset, $value) should either be compatible with ArrayAccess::offsetSet(mixed $offset, mixed $value): void, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/HasDataTrait.php#36	
2022-10-16T21:04:25+0200
Fehler	PHP	Error: Return type of & Aws\Endpoint\Partition::offsetGet($offset) should either be compatible with ArrayAccess::offsetGet(mixed $offset): mixed, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/HasDataTrait.php#26	
2022-10-16T21:04:25+0200
Fehler	PHP	Error: Return type of Aws\Endpoint\Partition::offsetExists($offset) should either be compatible with ArrayAccess::offsetExists(mixed $offset): bool, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/HasDataTrait.php#41	
2022-10-16T21:04:25+0200
Fehler	PHP	Error: Return type of Aws\Api\AbstractModel::offsetUnset($offset) should either be compatible with ArrayAccess::offsetUnset(mixed $offset): void, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/Api/AbstractModel.php#46	
2022-10-16T21:04:25+0200
Fehler	PHP	Error: Return type of Aws\Api\AbstractModel::offsetSet($offset, $value) should either be compatible with ArrayAccess::offsetSet(mixed $offset, mixed $value): void, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/Api/AbstractModel.php#36	
2022-10-16T21:04:25+0200
Fehler	PHP	Error: Return type of Aws\Api\AbstractModel::offsetGet($offset) should either be compatible with ArrayAccess::offsetGet(mixed $offset): mixed, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/Api/AbstractModel.php#30	
2022-10-16T21:04:25+0200
Fehler	PHP	Error: Return type of Aws\Api\AbstractModel::offsetExists($offset) should either be compatible with ArrayAccess::offsetExists(mixed $offset): bool, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/Api/AbstractModel.php#41	
2022-10-16T21:04:25+0200
Fehler	PHP	Error: Return type of Aws\HandlerList::count() should either be compatible with Countable::count(): int, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/HandlerList.php#308	
2022-10-16T21:04:25+0200
Fehler	PHP	Error: Return type of Aws\Result::count() should either be compatible with Countable::count(): int, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/HasDataTrait.php#56	
2022-10-16T21:04:18+0200
Fehler	PHP	Error: Return type of Aws\Result::getIterator() should either be compatible with IteratorAggregate::getIterator(): Traversable, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/HasDataTrait.php#13	
2022-10-16T21:04:18+0200
Fehler	PHP	Error: Return type of Aws\Result::offsetUnset($offset) should either be compatible with ArrayAccess::offsetUnset(mixed $offset): void, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/HasDataTrait.php#46	
2022-10-16T21:04:18+0200
Fehler	PHP	Error: Return type of Aws\Result::offsetSet($offset, $value) should either be compatible with ArrayAccess::offsetSet(mixed $offset, mixed $value): void, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/HasDataTrait.php#36	
2022-10-16T21:04:18+0200
Fehler	PHP	Error: Return type of & Aws\Result::offsetGet($offset) should either be compatible with ArrayAccess::offsetGet(mixed $offset): mixed, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/HasDataTrait.php#26	
2022-10-16T21:04:18+0200
Fehler	PHP	Error: Return type of Aws\Result::offsetExists($offset) should either be compatible with ArrayAccess::offsetExists(mixed $offset): bool, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/HasDataTrait.php#41	
2022-10-16T21:04:18+0200
Fehler	PHP	Error: Aws\Credentials\Credentials implements the Serializable interface, which is deprecated. Implement __serialize() and __unserialize() instead (or in addition, if support for old PHP versions is necessary) at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/Credentials/Credentials.php#8	
2022-10-16T21:04:18+0200
Fehler	PHP	Error: Return type of Aws\Command::getIterator() should either be compatible with IteratorAggregate::getIterator(): Traversable, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/HasDataTrait.php#13	
2022-10-16T21:04:18+0200
Fehler	PHP	Error: Return type of Aws\Command::count() should either be compatible with Countable::count(): int, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/HasDataTrait.php#56	
2022-10-16T21:04:18+0200
Fehler	PHP	Error: Return type of Aws\Command::offsetUnset($offset) should either be compatible with ArrayAccess::offsetUnset(mixed $offset): void, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/HasDataTrait.php#46	
2022-10-16T21:04:18+0200
Fehler	PHP	Error: Return type of Aws\Command::offsetSet($offset, $value) should either be compatible with ArrayAccess::offsetSet(mixed $offset, mixed $value): void, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/HasDataTrait.php#36	
2022-10-16T21:04:18+0200
Fehler	PHP	Error: Return type of & Aws\Command::offsetGet($offset) should either be compatible with ArrayAccess::offsetGet(mixed $offset): mixed, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/HasDataTrait.php#26	
2022-10-16T21:04:18+0200
Fehler	PHP	Error: Return type of Aws\Command::offsetExists($offset) should either be compatible with ArrayAccess::offsetExists(mixed $offset): bool, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/HasDataTrait.php#41	
2022-10-16T21:04:18+0200
Fehler	PHP	Error: is_readable(): open_basedir restriction in effect. File(//.aws/config) is not within the allowed path(s): (/usr/share/webapps:/home/http/www/cloud.rfreyt.ag/data:/etc/webapps:/usr/lib/php:/var/lib/nextcloud:/var/log/nextcloud:/tmp) at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/Retry/ConfigurationProvider.php#158	
2022-10-16T21:04:18+0200
Fehler	PHP	Error: Return type of Aws\Endpoint\Partition::offsetUnset($offset) should either be compatible with ArrayAccess::offsetUnset(mixed $offset): void, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/HasDataTrait.php#46	
2022-10-16T21:04:18+0200
Fehler	PHP	Error: Return type of Aws\Endpoint\Partition::offsetSet($offset, $value) should either be compatible with ArrayAccess::offsetSet(mixed $offset, mixed $value): void, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/HasDataTrait.php#36	
2022-10-16T21:04:18+0200
Fehler	PHP	Error: Return type of & Aws\Endpoint\Partition::offsetGet($offset) should either be compatible with ArrayAccess::offsetGet(mixed $offset): mixed, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/HasDataTrait.php#26	
2022-10-16T21:04:18+0200
Fehler	PHP	Error: Return type of Aws\Endpoint\Partition::offsetExists($offset) should either be compatible with ArrayAccess::offsetExists(mixed $offset): bool, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/HasDataTrait.php#41	
2022-10-16T21:04:18+0200
Fehler	PHP	Error: Return type of Aws\Api\AbstractModel::offsetUnset($offset) should either be compatible with ArrayAccess::offsetUnset(mixed $offset): void, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/Api/AbstractModel.php#46	
2022-10-16T21:04:18+0200
Fehler	PHP	Error: Return type of Aws\Api\AbstractModel::offsetSet($offset, $value) should either be compatible with ArrayAccess::offsetSet(mixed $offset, mixed $value): void, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/Api/AbstractModel.php#36	
2022-10-16T21:04:18+0200
Fehler	PHP	Error: Return type of Aws\Api\AbstractModel::offsetGet($offset) should either be compatible with ArrayAccess::offsetGet(mixed $offset): mixed, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/Api/AbstractModel.php#30	
2022-10-16T21:04:18+0200
Fehler	PHP	Error: Return type of Aws\Api\AbstractModel::offsetExists($offset) should either be compatible with ArrayAccess::offsetExists(mixed $offset): bool, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/Api/AbstractModel.php#41	
2022-10-16T21:04:18+0200
Fehler	PHP	Error: Return type of Aws\HandlerList::count() should either be compatible with Countable::count(): int, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice at /usr/share/webapps/nextcloud/3rdparty/aws/aws-sdk-php/src/HandlerList.php#308	
2022-10-16T21:04:18+0200
Warnung	fulltextsearch	Exception while cronIndex: OCA\FullTextSearch\Exceptions\PlatformNotSelectedException - Admin have not selected any IFullTextSearchPlatform	
2022-10-16T20:55:02+0200
Warnung	no app in context	Sabre\DAV\Exception\NotFound: File with name /SofortUpload/1632060925024_39581928.mp4 could not be located	
2022-10-16T20:52:48+0200
Fehler	camerarawpreviews	Exception: Unable to find preview data: /var/lib/nextcloud/apps/camerarawpreviews/vendor/exiftool/exiftool/exiftool.bin -json -preview:all -FileType '/tmp/oc_tmp_PqUJeJ' -> [{ "SourceFile": "/tmp/oc_tmp_PqUJeJ" }] 	
2022-10-16T20:45:39+0200
Fehler	camerarawpreviews	Exception: Unable to find preview data: /var/lib/nextcloud/apps/camerarawpreviews/vendor/exiftool/exiftool/exiftool.bin -json -preview:all -FileType '/tmp/oc_tmp_amtD5w' -> [{ "SourceFile": "/tmp/oc_tmp_amtD5w" }] 	
2022-10-16T20:45:38+0200

The output of your config.php file in /path/to/nextcloud (make sure you remove any identifiable information!):

PASTE HERE

The output of your Apache/nginx/system log in /var/log/____:

PASTE HERE

Output errors in nextcloud.log in /var/www/ or as admin user in top right menu, filtering for errors. Use a pastebin service if necessary.

PASTE HERE