Encryption corrupts documents after some hours

Describe the bug
I and co-workers wrote a documentation about a network in nextcloud office. After about 4 hours of writing the document suddenly went blank. I then tried to restore a older version with the "versions" feature, all corrupted. I then tried restarting NGinx and PHP, didn't help. After that I tried downloading it and open it with Microsoft Word. Word couldn't open it, because it was corrupted. Today it happend again with an Excel file.

To Reproduce
Steps to reproduce the behavior:

1. Open Word/Excel/(probably also PowerPoint) file
2. Write something
3. After some hours there are 2 possibilities: either it gets corrupted while you still write or it gets corrupted while it's closed.

Expected behavior
It should not get corrupted.

Client details:

• OS: Debian 12
• Browser: Microsoft Edge

Server details

Operating system: Debian 12

Web server: NGinx

Database: MariaDB

PHP version: PHP 8.1

Nextcloud version: 27.0.2

Version of the richdocuments app 8.1.1

Version of Collabora Online 23.5.305

https://paste.miichelle.moe/upload/snail-shark-bee

Start with the linked data/nextcloud.log output and the reported richdocuments, Collabora Online, PHP, Nginx, and MariaDB versions. Investigate whether the corruption can be reproduced for Word or Excel files after several hours, and consider the issue complete only when documents remain readable during and after editing.