Nextcloud iOS app can't download and print in collabora

Hello everyone,

I have encountered a problem with the nextcloud iOS app when using collabora:
As soon as I open any text file in the built-in collabora editor, and I try to download via “Download As” or “File -> Print”, I receive the following error: “Error: 404 The requested resource could not be found”.
Further, the “welcome to a new version of collabora” message opens up again each time I re-open the document.

Editing works fine.

I am running Collabora CODE as a separate instance in docker with an nginx reverse proxy.

Do you have any ideas on how to fix these issues? Especially the download functionality would be really great.