I want to bring this up again.
As we are hosting at Hetzner we are used to get the usual notifications from the BSI about rpcbind running on a fresh server.
In the past it was a one-shot to just disable and stop the service as described above.
But now i received the warning the third time and I stopped and disabled the service after the first notification.
It seems that either a crontab or something starts it automatically.
The server has a uptime of 32 days as I am writing.