Last school year we ended up rolling back AP firmware because Apple TVs on our student wifi began having connection issues immediately after updating our MRs. This summer we went ahead and updated all APs to 30.6. We are again having connection issues. All of the ATVs are visible to devices (MacBooks and ipads on the same wifi), but when trying to connect it either takes forever, never asks for the passcode (enforced by MDM) or does nothing. And of course it's random among versions (some tvos 17.5.1 work great, some don't for example). If I remove the wifi settings from an ATV (forcing the device and ATV to use a direct wifi connection) everything works great.
The wifi is pretty straight forward, bridged, WPA2 password, no layer 7 firewall rules and the usual allows for bonjour, dns, etc. I don't believe it is a firewall issue as some connections work just fine.
Thanks for listening