I have a Playbar on a TV in a room which also has speakers fed from a connect amp. When streaming the radio with both in a group the Playbar will cut out for around 5 - 10 seconds then cut back in, the speakers connected to the connect amp do not cut out.
The playbar is hard wired with the wifi disabled, the TV is switched off. I have also tried with the wifi left on same result.
When playing sound from the TV via optical there is no issue.