I have this following error message in the Nextcloud Office setting dashboard:
Could not establish connection to the Collabora Online server.
Failed to connect to the remote server: Could not find urlsrc for application/vnd.openxmlformats-officedocument.wordprocessingml.document in WOPI discovery response
I use the official nginx configuration from Nextcloud. For any further needed information, just ask, and I will try to deliver it. Despite the CODE integration, Nextcloud runs fine.
Sadly not yet. I did not have the time to do more investigation, but in the near future I need to install a new Nextcloud server anyway, then I will look and report back in this thread.