Support intro
Sorry to hear you’re facing problems 
help.nextcloud.com is for home/non-enterprise users. If you’re running a business, paid support can be accessed via portal.nextcloud.com where we can ensure your business keeps running smoothly.
In order to help you as quickly as possible, before clicking Create Topic please provide as much of the below as you can. Feel free to use a pastebin service for logs, otherwise either indent short log examples with four spaces:
example
Or for longer, use three backticks above and below the code snippet:
longer
example
here
Some or all of the below information will be requested if it isn’t supplied; for fastest response please provide as much as you can 
Nextcloud version (eg, 12.0.2): 16.04.1
Operating system and version (eg, Ubuntu 17.04): 18.04
Apache or nginx version (eg, Apache 2.4.25): NGINX 1.17.4
PHP version (eg, 7.1): 7.3.9
The issue you are facing:
please help me deal with downloading large files through the nextcloud client.
The problem is that files larger than 10GB are uploaded to the cloud, but every time the client writes “Connection timed out”, the file is still uploaded to the cloud, and the error disappears after a while.
Tell me why this is happening?
Is this the first time you’ve seen this error? (Y/N):
Steps to replicate it:
The output of your Nextcloud log in Admin > Logging:
PASTE HERE
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