I use the Bang & Olufsen M5 speakers (with automatic firmware update) at home, which supports Airplay. Until now, I have had no problem streaming all music and sounds (including system sounds) from Macbook Pro 2016 (playing movies from the web/flash drive/web, Youtube videos, online radio, etc) into it. Until now, when updated to MacOS Big Sur 11.4, playback only works in applications that directly offer streaming via Airplay (for example, Apple Music, Podcast, and that's all). I tried connecting the speaker to my other 2015 Macbook, on which I have Big Sur 11.3.1 and everything works perfectly here.
So the fault cannot be in the speaker, but in the system itself - is there a solution or reason that caused this problem?
Yesterday I tried to connect via Airplay to the TV Samsung UE55RU7172, the image transmission works, but the sound only plays from Macbook - so the problem is definitely in the Big Sur 11.4 update.
I also tried the NVRAM reset, which didn't help. I restarted the speaker to factory settings - it still doesn't work under Big Sur 11.4 (on Big Sur 11.3.1 it works without a problem, the same goes for TV). I reset the wifi router - the problem remains.
I guess I just have to hope for a fix in the next update (or am I wrong?)..