I can report the same. Once I set sys-net-wifi and sys-firewall-wifi to be based off debian-11 it worked fine. (Most people should ignore the -wifi suffixes; I have different networking for the two networks I am connected to, to keep them separated.)
In theory setting dom0 up to update through whonix is also an option. That does function and would allow me to abandon debian 11 altogether, but then I could not update the whonix template to save my life (Can't update whonix-gw-16). Seeing that update icon ON all of the time whether or not there was something updateable that needed updating was a non-starter. (It’s like a “check engine” light that stays on even though you’ve attempted to maintain the minor thing it’s complaining about…you have no idea when a bigger, much more significant problem comes along, then.) Anyhow, if you don’t have problems updating whonix, it’s definitely an option vs. keeping debian-11 around.