I have similar issue though with a bit different symptoms. In my case HADashboard cannot run scripts from mode widget. The same script run from script widget works ok. It happens after system restart (entire jail) and is back to normal when I restart addpaemon service. The following entries show up in appdaemon_daemon.log:
2020-10-27 18:10:02.612065 WARNING AppDaemon: Unknown domain (default/script) in call_service from stream
2020-10-27 18:11:14.906043 WARNING AppDaemon: Unknown domain (default/script) in call_service from stream
The appdaemon was installed as part of the HA Core community plugin to FreeNAS and so far was working ok. So it is installed in a FreeNAS jail in a virtualenv:
Testing virtualenv...
CWD: /usr/local/share/appdaemon
Python 3.8.6
AppDaemon 4.0.5
HA Core is 0.116.2 release.
Any hints? Iām pretty sure it was working ok in one of previous versions running on python 3.7 but not sure exactly when it got broken.