Hi @dhpferguson
Welcome to the Sonos Community!
I’m sorry to hear of this issue you are having with audio cutting out when you change input sources on your Sony TV. It sounds most annoying.
I had not heard of any known incompatibility issues regarding Sony TVs, so I did a search through my internal documentation on your TV model and found no mentions of it whatsoever. Thinking one of our support agents had made a mistake, I then looked for existing support cases under your Sonos account. I could only find two cases, however, neither of which got past the chat bot. If there was another case where you managed to speak to a person, could you please send the case number to me in a Direct Message (please don't post it here in a public area, thanks) and I’ll look to providing some feedback to the agent involved.
To be clear, there is no known compatibility issue with your Sony TV and Sonos soundbars.
If you did not manage to get to speak to a support agent, then I recommend you try to do so - some in-depth troubleshooting may be required, and that will involve asking the Arc Ultra what is going on via system diagnostics.
I hope this helps, and I look forward to being able to assist you further, if need be.