I'm having this same issue. Just took delivery and set up the soundbar to my QN85DA TV today. It's connected via eArc. Works fine with Amazon Music and so far it worked fine with Amazon Prime Videos played through that app. But I'm watching a movie through Disney Plus and the soundbar cuts out about every 4 or 5 minutes, flashes eArc and Dolby Atmos lasts 2 seconds and then repeats the same flash. Will work for about 4 or 5 minutes and do it all over again. Both are connected via SamsungThings and as far as I can tell both have updated software. This should not be an issue for what I paid, almost 3k, to have BOTH these products work together since this soundbar was recommended for these types of TVs. If I switch to WiFi connection I get the same issue, but nothing flashes on the soundbar. Would be nice if Samsung stepped in to answer why this is happening.