sonos arc keep switching from eARC to normal HDMI, back and forth

Sure sounds abnormal. I’d check both the TV and the Sonos for updates, then reboot them both, by unplugging each from the wall for at least two minutes. 

This started happening to me two weeks ago as well and I haven’t seen anything else about it. I initially thought it was my internet causing the sound to cut in and out. But I realized it was the my sonos arc switching from eARC to HDMI-ARC and back when I saw the the output switch from eARC to HDMI-ARC and I lost audio at the same time. What is weird is I also have a 2022 Samsung TV, specifically a s95B which hasn’t received an update for more than a year. My sonos is system is also up to date. I also use the HDMI chord that came with the sound bar.

Mine seems to do it only when I turn my TV on. It goes away after a couple of minutes, or if I switch the output to tv speakers. It auto switches back to eARC after.

Have you submitted a system diagnostic within 10 minutes of experiencing this problem, and called Sonos Support to discuss it?

There may be information included in the diagnostic that will help Sonos pinpoint the issue and help you find a solution.

When you speak directly to the phone folks, they have tools at their disposal that will allow them to give you advice specific to your network and Sonos system.

There is a known issue with some Samsung TVs and their CEC implementation.

You could switch to optical to avoid it, until it gets fixed.

Thanks controlav. You are probably right but that just doesn’t make sense to me. I have had the tv and sound system for two years with no problems until a couple weeks ago. And there have been no new recent updates to either item. Why would it be a problem now? Not saying you are incorrect, it is a genuine question. I don’t have a lot of knowledge about this topic (i.e. Samsung tv having cec issues). 
 

I have a Sonos system with an arc, a sub, and two one sl’s for surround. Does switching to optical affect the other products in my overall system setup? 

So I was incorrect. I was looking at when an update was last checked for, which was over a year ago. Not when an update was applied. So yes, the tv is on version 1602.3, which is the most current. Seems like you are correct, I am seeing others have the same eARC desync issues after this update over on Reddit. Glad to know it’s not my Sonos products going bad! 
 

Thanks for the help

I have an LG TV and I’m having the same problem described by Samsung users.  In the past week when the TV is first turned on, I won’t get any audio for awhile and then the sound starts popping and coming and going for awhile.  Eventually the sound system stabilizes and is normal again.  I have the sonos set on zero volumn during this time because the sonos and TV receiver system don’t align.  This whole process can be fixed by manually turning off the sonos soundbar or unpluging it.  I can also do short term fixes by unpluging the sonos from the E-ARC port, then plugging ti back in and reconnecting with the sonos app.  

The next time you experience it, submit a system diagnostic within 10 minutes, and call Sonos Support to discuss it.

There may be information included in the diagnostic that will help Sonos pinpoint the issue and help you find a solution. Especially if it’s a Sonos issue, in some way. 

When you speak directly to the phone folks, they have tools at their disposal that will allow them to give you advice specific to your network and Sonos system.