Nextcloud Office keeps files "locked"

Hi everyone

I’m pretty new to selfhosting / nextcloud, so sorry for all the incompetences.
As far as i can tell i managed to install nextcloud behind a nginx-proy, including nextcloud office with integrated CODE-Server. In the Brower GUI everything works fine.

Since installing office and Code Server, my Android-Client seems to behave strange. When i open a word/excel/.. file it seems to load said file forever. When i leave the loading sceen, the file stays “locked” (Displays: “Locked by the App Nextcloud Office (Collabora)” with a little lock in the App).
In Browser i can open and work in it. But im still beeing displayed as Working in the File on my phone (top right corner).

Thankfull for every hint…

It seems to be a known bug with NC 34.0.0:

Thanks a lot.

Will keep an Eye on those Repos.