Hi,
For you information, in order to update all your TemplateVM/StandaloneVM having python3.9 like latest bullseye, Fedora 33, Gentoo, etc. with Salt or the Qubes Update widget, the mgmt-dvm needs to be switched to Fedora 33 template.
The technical reason can be found in IPv6AddressScoped: define self._scope_id for python3.9+ compatibility by fepitre · Pull Request #58518 · saltstack/salt · GitHub.
Best regards,
Frédéric