I was having a few glitches, because I had too many things drawing Wifi bandwith (Apple TV 4K, Wiim amp Ultra, two Wiim sound lites and Wiim sub pro). Live and learn!
I wired everything with ethernet cables. No big thing; quality ethernet cables are not expensive and I was able to hide most of them.
The result, no more glitches and the system sounds MUCH better! The picture quality on my LG C6H is also improved.
Wifi is convenient, but if you can, use an ethernet cable.