Course Restore in Moodle 4 doesn't seem to work

Hello

I'm on Moodle version 4.0.2+ (Build: 20220722).

I tried to do a course restore from a Moodle 3 course backup and that failed.

Now I've tried backing up a course in the current Moodle - with no users, no activities etc. so about 20kb of data - so a backup of a course in the Moodle 4 and it seems to be getting stuck somewhere. I left it running for 4 hours yesterday, just to be sure I wasn't rushing it - yes I know an insane amount of time, but our Moodle is a bit slow.

Anyway I tried again with debug running and I'm getting nothing in the logs or on screen.

Any ideas how I fix it as I have no idea what is wrong with it. It just sits there on the performing restore page.

Thank you.

Heather