Issue with downloading folders over mobile network – downloads interrupted randomly

ℹ️ Support
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Hi everyone,

We’ve been experiencing a recurring issue when downloading entire folders (as ZIP archives) in Nextcloud – both through web browsers and official Nextcloud apps (desktop and mobile).

Problem description:
When downloading folders over a mobile network, the download often fails at random points – sometimes after 100 MB, sometimes after 1 GB – with a message like “Check your internet connection” appearing.
When using a wired/stationary internet connection, the issue occurs much less frequently, but still happens occasionally.

Tests we’ve conducted:

  • The issue occurs regardless of browser or operating system.
  • It also affects downloads through the official Nextcloud mobile and desktop apps.

Environment details:

  • Nextcloud version: 31.0.3
  • OS: Ubuntu Server
  • PHP: 8.3.6
  • Apache: 2.4.58
  • Database: MariaDB 10.11.11
  • The data/ folder is mounted from a separate Synology file server via /mnt/nextcloud_data – stable local connection.
  • Users connect to the server via OpenVPN, using a domain name (DNS A record pointing to internal IP).
  • SSL is handled by an internal domain controller (certificate is valid and working properly).

PHP configuration (/etc/php/8.3/cli/php.ini and /etc/php/8.3/apache2/php.ini):

memory_limit = 4G
upload_max_filesize = 10G
post_max_size = 12G
max_execution_time = 3600
output_buffering = Off


**Apache configuration (`/etc/apache2/apache2.conf`):**

Timeout 600  
LimitRequestBody 0  
KeepAlive On  
MaxKeepAliveRequests 100  
KeepAliveTimeout 5

What we’ve done so far:

  • We’ve tuned the server and PHP settings to support long downloads and large files.
  • Verified that our network, VPN, and storage infrastructure are working correctly.
  • Tried different environments and devices – the issue persists.

We believe the problem may lie within the Nextcloud backend or how it handles ZIP downloads over unstable networks.
We would greatly appreciate any help, advice, or suggestions on how to further investigate or resolve this issue.

Thanks in advance! :pray:
Best regards,