Hello @Kjell_Rune, welcome back!
I am sorry to hear you are experiencing issues with your Sonos Arc connected to your Samsung TV.
On a first read, this sounds like a CEC conflict. What other devices are connected via HDMI to your TV?
Can you please try and test out if the same issue occurs when only the Sonos Arc is connected to your Samsung TV on the eARC HDMI port? If this resolves it, you might need to disable CEC functions on the 3rd party devices connected to your TV. A full reboot of your TV would also help, removing the power cable → wait 15-20 seconds → plug power cable back in.
This type of setup combination (Samsung Frame & Sonos Arc) is pretty common among our customers, I believe if this was an issue with the Sonos Arc, more people would have reached out to raise this.
Feel free to reply here with any updates, although I would suggest to first Submit Diagnostics within 10 minutes of reproducing the experience and reach out to our Support Team for some live troubleshooting.
They have tools at their disposal to provide you with information and advice specific to your system and what it reports.
I hope this helps.
This happens to my Arc/Frame & Apple TV setup from time to time as well. I often times have to reboot the Arc and or the TV/Apple TV in order to fix.
There have also been other issues as well that seem to relate to Atmos and/or CEC between devices. For instance often times after playing Atmos music on Music App & Apple TV through the Frame/Arc surround setup for a bit of time a “warble” sound kicks in. Sorry, I don't know how to explain other than that! It’s very noticeable/loud and I have to either turn Atmos off and back on on the Apple TV or temporarily airplay to one of my other airplay speakers so as to “force” Atmos off. I then turn the other airplay speaker off so as only my Arc/surround setup takes back over and Atmos kicks back in without the “warble”. Happens I estimate once an hour or so randomly.
Doesn't seem to happen with non Atmos audio.
No idea what is happening or how to fix. Very frustrating.
Just dumped a log file to Sonos while this was going on, and nothing wrong with the setup as far as Sonos tech can tell.. Sooo… back to Samsung support i guess.
Let the pointing games begin 
Yes.. soooo… I´ve gone through sonos support, as always very helpful and real good service. They went through my setup and found it to be just grand. Then back to Samsung, which also gave superb service. Two hours on chat and phone. Did a HDMI reset on all ports and reseated the cables in the OneConnect, no effect. Did a factory reset from the menu on my tv, no effect. Then we did a “deep” factory reset initiated from remote support and there it was.. all ok. That is, until next full power cycle and the problem was back. So the next thing to do before Samsung escalated this issue to level 2 support, they asked me to test the Arc on another TV. As I started to disconnect the Arc I noticed the HDMI was just a little bit askew, barely visible… I´m quite embarrassed to say this, but reseating the HDMI on the Arc fixed the problem. Good grief.. the first thing I should have checked was the last thing I checked.
Lessons learned: No matter how competent and knowledgable I like to think I am… ALWAYS check the basics first…
Thanks to both Sonos and Samsung for their patience and service.
