Nextcloud Office document cannot be edited from a shared link but ok if connected

Nextcloud version (eg, 20.0.5): 23.0.4
Operating system and version (eg, Ubuntu 20.04): debian 10
Apache or nginx version (eg, Apache 2.4.25): Apache 2.4.38
PHP version (eg, 7.4): 7.3

The issue you are facing:
Documents created with Nextcloud can be edited if connected but if you send a shared link to some people they cannot edit it … of course link has been set as authorizing edition.

Is this the first time you’ve seen this error? (Y/N): Yes, IIRC it was working with OO

Steps to replicate it:

  1. create a new document (text .odt or spreadsheet .ods)
  2. you can edit it from within NC
  3. create a shared link
  4. send it to somebody that does not have an account or is not signed in … if he tries to edit, NC is proposing download intead of edition

Which particular variation of Collabora are you using, such as the standalone docker container or the built-in Collabora CODE app?

Try checking the documentation and github repo issues related to whichever variation you are using.

Self installed server with:

Collabora Online - Built-in CODE Server 21.11.402

Nextcloud Office 5.0.4