Hey @ijeoijwoeic2eij2. Welcome to the forum.
Have you tried following the instructions:
There is also this fantastic Nextcloud “Wiki” topic that might help:
They go into even more testing between Nextcloud<->Collabora + proxies/troubleshooting things.
Might also help if you can give exact version numbers too of:
- Collabora Online + richdocuments
- Nextcloud
- Your OS + OS version
- […]
Great! Sounds like one step in the right direction!