Seahub doesn't start after Debian Upgrade Buster to Bullseye

Hey guys,
after upgrading debian to bullseye on my raspberrypi 4 I can’t start seahub anymore:

ImportError: cannot import name ‘_mysql’ from partially initialized module ‘MySQLdb’ (most likely due to a circular import) (/home/seafile/seafile-server-8.0.7/seahub/thirdpart/MySQLdb/init.py)

Any Idea what to do?