So my QNAP TS-251B is fixed. Not quite sure how tbh. I read a write-up that walked you through a reset but advised that it would wipe the drives. Luckily, I could still access the NAS from the cloud so downloaded all the important stuff. anyway, I bit the bullet and pressed reset and the voice said "Advanced Reset started" after a reboot, the NAS was back and so was my content \o/
Had to re-implement my personal configuration such as fixed IP etc but well chuffed it didn't wipe the drives.

Thomas mastodon (AP)
Good news! That's a great example why I have at least 2 backups.
Yeah, I'm thinking of getting another NAS to backup the TS-251B. I'd like the TS-364, but that's a bit overkill for home usage.