petergo,
I understand from what I read here on the Samsung forum:
https://eu.community.samsung.com/t5/tv/samsung-q80t-earc-issue/td-p/1807678
...that both Samsung and Sonos engineers are already looking into these matters.
There have been other audio cut-out issues with this particular Samsung TV, with non-Sonos hardware attached, one such example is briefly mentioned here:
https://us.community.samsung.com/t5/Qled-and-Frame/75-quot-Q80t-earc-audio-cutout/td-p/1360549
Anyhow, it’s not a ‘blame game’, it’s about the two manufacturers resolving this for their customers and Sonos have said elsewhere on this forum, that they have reached out to Samsung to get any matters resolved with them.
From a personal perspective, the Sonos Arc, Sub, & Surrounds are working fine with the LG OLED C9 TV that we have here at home and my colleagues Sonos Arc is also working fine with his Philips manufactured TV.
Anyway, I hope the manufacturers involved, are able to get these issues resolved for you.