Seafile pro 7.1.7 / Docker / mySql Error


since this afternoon I have the problem that Seafile logs this error:

waiting for mysql server to be ready: %s (2003, "Can't connect to MySQL server on 'db' ([Errno -2] Name or service not known)")

(The mySQL container is started)

Seafile and Seafile-mysql is installed as a docker container and has been running without problems until now.

I would be grateful if someone could give me a hint.