My first assumption when I see this is that it might be related to Nomad. We have run into issues before where it tries to mount a volume that is already in use, which leads to failed writes, or potentially even data corruption. This is extremely rare, but what you encountered matches the errors we got then.
I know you’ve probably seen us talk it up a lot on these forums, but migrating your app to V2 might help prevent this kind of error (if the stack you’re using is actually made for what you’re using it for, it works more reliably!)
Regardless, I’m happy it’s working now, although you might want to check any attached volumes for data integrity.