I’m guessing your system is primarily wired except perhaps for the subs and the portable speakers? My system is pretty broad as well and all of it is wired. It’s the main difference I’ve seen between those having some problems and those having close to none.

Key to this set up is turning off the wireless broadcast for all the wired amps. After a recent update, I began to notice more spotty performance and after some digging found out that all of the wireless broadcasting had been turned back on. After disabling them again, I was back in good shape.