This has resulted in the wallet needing to resync from scratch, and also the main node height being stuck at 274558/278218 for 24 hours and not moving:
I had a similar issue, I just had to re-install and copy over the files again. I think it took about 3 attempts before it finally decided to start working.
I did the same, based on another post that described only copying the blockchain DB. When I found the wallet wasn’t sync’d I found it’s DB and copied that too (I was running old and new in parallel until the new was validated as working).
I didn’t have any trouble though, stopped the new wallet, copied over from the old node and it sync’d right back up.