Cannot start Nextcloud Office

[mhepplewhite]

Hello
Collabora / Nextcloud Office used to work ok. Now I get either non-stop spinning wheel whilst “Loading” a file or the system gives up and says “Please try again later”. Mine is a simple installation on a Pi4, no Docker etc, with Ubuntu OS. As I say, used to work ok when at NC release 28 but not since going to 29 and now to 30. Administration Settings for Nextcloud Office look good (“Collabora Online server is reachable”) - had to go via ‘Use your own server’ setting ‘Disable certificate verification’ to avoid the cURL error (I am using a local certificate) (oddly, when I reload the Nextcloud Office administration settings page, ‘Use the built-in CODE’ becomes selected instead of ‘Use your own server’). WOPI set to 0.0.0.0/0.
I cannot glean anything from admin logging. I am at PHP8.2

Please offer some clues or guidance.

[wwe]

Please review collabora integration guide for details and troubleshooting list

[mhepplewhite]

Thank you very much. The 2 URLs under the “Nextcloud Office aka Built-In CODE” section yield sensible results. The section about ‘Apache reverse proxy’ is over my head - I am using Apache but have yet to figure out ‘tinkering’ beyond adding and enabling domains. I used NC administration to disable Nextcloud office (for the time being) so now files are offered for download rather attempting to start Collabora.
As I say, used to work, now doesn’t following upgrades. Is there a log file somewhere that will record the attempt to open a file with Collabora and the failure to start?
Cheers