Database migration lock after updating ghost

I realise that this question has already been asked before and I apologise for raising it again but none of the solutions have worked for me.

I’ve been running Ghost on a Google Cloud Run instance for a while and just recently updated from version 5.4.1 to version 5.25.2.
After the upgrade, the instance fails with the message

MigrationsAreLockedError: Migration lock was never released or currently a migration is running..

Initially I thought it was the MySQL version. I was running CloudSQL with MySQL 5.7 but I did an in-place upgrade to MySQL 8. That did not solve the issue.

The other fix I tried was setting the lock entry in the migrations_lock table to 0
i.e. UPDATE migrations_lock SET locked=0 WHERE lock_key='km01' and that hasn’t worked as well.

Downgrading versions doesn’t work either and I can’t go back to version 5.4.1 because of the vulnerability

I also came across the following comment Migration locked / migrations and migrations_lock are empty · Issue #9404 · TryGhost/Ghost · GitHub that suggested deleting the migrations and migrations_lock tables, but I’m very skeptical about that. The comment also has a number of downvotes.

Does anyone have any idea on how to fix this issue?

Did you ever resolve this?

Not really. We ended up exporting all our posts from MySQL 5.7 and running a whole new Ghost installation with MySQL 8, and wrote a script to write back all the posts to the new DB and link to the correct authors, comments etc. Luckily for us, it had only been running for a few weeks so we didn’t have a lot of posts and authors