This isn't answer to be fair, but it's further information as I see it - and comments are too short for the detail I wanted to post.

I'm also having the same problem (Android 15, Pixel 6 - Kernel build Sep 2 2024) which, I too, believe that at some relatively recent point in time was working for me (dabbling with esp32

I've tried via two APs I have (one is a RT-AX82U running stock, and the other is an of Linksys I had lying around with an oldish version of DD-WRT on it.

My Windows PC works fine, as does my partner's iPhone which suggests that it's the implementation of the DNS resolver in Android that's the culprit.

I did spot that around 5 weeks ago, several PRs were merged pertaining to mDNS, which does seem suspicious to me, although it's not clear what the cadence of updates to Android devices are, it would appear that these changes are more recent than the version I currently am running. https://android.googlesource.com/platform/packages/modules/DnsResolver/+log?s=ccdad891f6e896511c355de36ed287361c8f7a6f

I'm not a c++ dev, and the low-level net stack is something I'm not very knowledgeable about so my normal tack of dissecting the code isn't really an option. Hopefully the community can figure this one out!