DNS unconsistent in VMs

Hi there,
I run Qubes OS 4.1.2 with f37 AppVMs. DNS worked as expected until a few days.
In sys-net everything seems ok, I can resolve internal and external servers, /etc/resolve.conf looks plausible, iptables -t nat -L also. I run a Windows 11 HVM via sys-firewall and there also everything works as expected. But all AppVMs based on f37 including sys-firewall only resolve the external domains like www.google.com but not the local ones. The only thing missing in their /etc/resolve.conf is the search <domain.local> like in sys-net. If I set this manually it works!

Is this a known issue and is there solution? All I found so far seems differnt and solved in '22.

Please throw someone a clue banana! Thanks a lot.