NextCloud with IONOS (1und1) Unlimited - upload folders not possoble

I am new and i took a few houers arround to check, if there is a posting simmular to mine.
And sorry für my english, I tried my best, I am from germany.

I had an owncloud for two years (and the same problem), and now I installed a new and fresh nextcloud.
It works fine and I am inpressed of the funktions, great.

But I habe this problem: When uploading many files or folders (I tryed 30 files and 2 folders with a few subfolders), uploading is crashing after 5-8 files. I got an error-message an I am logged out.
Yesterday I installed the same system on my small V-Server, and there it workes fine, I think, it must be a problem with the IONOS-Space. (My V-Server hat not enough space to serve the cloud for a long time).
I can not find the problem.

A few infos about the system:
Nextcloud-Version: - actuell
Operating system: Linux (Linux info 3.0 #1337 SMP Tue Jan 01 00:00:00 CEST 2000 all GNU/Linux)
MySQL-Version: 5.7.28-log
PHP-Version: 7.4.5

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

$CONFIG = array (
  'instanceid' => 'xxxx',
  'passwordsalt' => 'xxxx',
  'secret' => 'xxxx//FSQ7dA/rf58S',
  'trusted_domains' => 
  array (
    0 => '',
  'datadirectory' => '/homepages/38/d78627184/htdocs/nextcloud/data',
  'dbtype' => 'mysql',
  'version' => '',
  'overwrite.cli.url' => '',
  'dbname' => 'xxxx',
  'dbhost' => 'xxxx',
  'dbport' => '',
  'dbtableprefix' => 'oc_',
  'mysql.utf8mb4' => true,
  'dbuser' => 'xxxx',
  'dbpassword' => 'xxxx.9',
  'installed' => true,
  'mail_from_address' => 'noreply',
  'mail_smtpmode' => 'smtp',
  'mail_sendmailmode' => 'smtp',
  'mail_domain' => '',
  'mail_smtphost' => '',
  'mail_smtpport' => '465',
  'mail_smtpsecure' => 'ssl',
  'mail_smtpauth' => 1,
  'mail_smtpname' => '',
  'mail_smtppassword' => 'xxxx',

Thanx and greetings from berlin


I can find this in Admin-Panel:

Error documentserver_community OCA\DocumentServer\Document\DocumentConversionException: # # Fatal process OOM in Zone # Received signal 4 ILL_ILLOPN 2b71a823b6b9 ==== C stack trace =============================== [0x2b71a823c902] [0x2b71a9d1e890] [0x2b71a823b6b9] [0x2b71a7a5714d] [0x2b71a7a5734c] [0x2b71a7ea8b88] [0x2b71a7a8faa4] [0x2b71a7daf5c3] [0x2b71a7d9ecd3] [0x2b71a7d9efaf] [0x2b71a7d9f759] [0x2b71a7da0644] [0x2b71a7da0a6c] [0x2b71a7da15c9] [0x2b71a7da7e26] [0x2b71a7da47aa] [0x2b71a7da4e18] [0x2b71a7da5a53] [0x2b71a7dba6f7] [0x2b71a7da2aaf] [0x2b71a7da301f] [0x2b71a7da8f55] [0x2b71a7dae97c] [0x2b71a7daf435] [0x2b71a7d9ecd3] [0x2b71a7d9efaf] [0x2b71a7d9f759] [0x2b71a7da0644] [0x2b71a7da0a6c] [0x2b71a7da15c9] [0x2b71a7da7e26] [0x2b71a7da47aa] [0x2b71a7da5a53] [0x2b71a7da400f] [0x2b71a7d9eb9b] [0x2b71a7d9efaf] [0x2b71a7d9f759] [0x2b71a7da0644] [0x2b71a7da0a6c] [0x2b71a7da15c9] [0x2b71a7da7e26] [0x2b71a7da47aa] [0x2b71a7da5a53] [0x2b71a7dba6f7] [0x2b71a7da2aaf] [0x2b71a7da301f] [0x2b71a7da8f55] [0x2b71a7dae97c] [0x2b71a7daf435] [0x2b71a7d9ecd3] [0x2b71a7d9efaf] [0x2b71a7d9f759] [0x2b71a7da0644] [0x2b71a7da0a6c] [0x2b71a7da15c9] [0x2b71a7da7e26] [0x2b71a7da47aa] [0x2b71a7da5a53] [0x2b71a7da400f] [0x2b71a7d9eb9b] [0x2b71a7d9efaf] [0x2b71a7d9f759] [end of stack trace] Illegal instruction