With the incremental roll out of Apple Intelligence features it is a low priority bug for Apple. AirPlay does not require local network device access permissions. As Apple Music /airplay works fine I fear it will be some time for a fix. Apple received bug reports on this issue after the release candidate was issued so all we can we do is wait patiently.
Has anybody tried disabling ‘Limit IP Address Tracking’ for both the Ethernet and WI-FI connection? (found in the ‘Details’ for the connection)… This was brought-up as a working fix in this Apple Support Forum thread:
https://discussions.apple.com/thread/255765230?sortBy=rank&page=1
I am not sure. In the past, I have reported feedback on music related stuff that I thought was really niche, but it was resolved. You won’t get a message back, but just report the problems. If enough people do, they will listen.