[brudgers]

Ok, it sucks. Your options are to leave or wait it out. Either way, the pressure does not seem blatently irrational.

a big step down from my US salary. The main reason for the move was to get a visa and work in Europe

If that’s common knowledge in the team, it is probably is not particularly good for morale. If you tell people you are slumming out of self interest, it is unlikely to win friends, but will influence them.

The part that feels off is that the "messy" code they're pointing to is a direct result of the constant pivots and the "move fast" culture we've all been working in.

That’s a reason, not an excuse. Being senior means there are no excuses.

My manager's own PRs have introduced critical bugs that I've had to stay late to fix.

So what? Everyone makes errors. This smells like an issue with your boss.

Any advice

The question suggests cultural fit issues. Or are you the kind of person the team wants to work with. Good luck.