I am having a similar issue to this individual:
I have the following setup:
1. Sonos One
2. Apple TV 4k
I have the Apple TV setup to broadcast to the Sonos One. I plugged both of these devices into a wired network for this test.
On Sunday I was watching NFL Sunday Ticket on my Apple TV 4K. I set the audio output to be Apple TV (this utilizes the HDMI output) and I can add four games to the screen and everything runs great. When I change the audio output to the Sonos One all of the games freeze. I may get some audio on the Sonos. I cannot even add four games without them freezing when I initially have the audio output set to the Sonos.
I can watch a single video on HBO GO or Netflix and broadcast it to the Sonos without issue. Anyone have any ideas about why this might be happening?