Salt doesn't work anymore in Factory, communication with Minions not possible.

Minions report itself to the master, you can accept the key, but aftwards, you
only get timeouts:

# salt '*' test.ping
/usr/lib/python3.8/site-packages/salt/ext/tornado/httputil.py:107:
DeprecationWarning: Using or importing the ABCs from 'collections' instead of
from 'collections.abc' is deprecated since Python 3.3, and in 3.9 it will stop
working
  class HTTPHeaders(collections.MutableMapping):
kubic-2.demo:
    Minion did not return. [No response]
ERROR: Minions returned with non-zero exit code


I cannot find anything more/relevant in the logs.