I am a very Tech savvy AV person, not a pro but very good non-the-less. I have been reading all of these posts and I have determined that my problem is 100% a Sonos amp issue, or a Sonos issue period. I also believe that after reading these posts that this problem is something that Sonos needs to address across all products, possibly. 100% of my products have the same issue.

I have 3 different TVs. SONY, TCL, Samsung. I have 1 Polk 5.1 Surround (2 years old) and 4 Sonos Amps (brand new). All HDMI cables are 2.1 (brand new).

All TVs work perfectly with Polk system using Arc or eArc. I can connect, disconnect and reconnect to Polk system. I can power off, power on, have gone through power outages, etc. Bottom line all TVs work Perfectly with the Polk system via HDMI ARC or eArc and also work perfectly with Optical. Polk is becoming a personal favorite very quickly.

Now, lets discuss the 4 Sonos Amp amplifiers I have.

1. all stream music perfectly.
2. can connect all amps to wifi
3. can group all amps or play them separately.
4. All amps work with TVS using Optical perfectly.
5. All amps have issue using HDMI Arc.

I had one of the Sonos Amps working using a TCL Tv and HDIM Arc for a while but from time to time the audio would get choppy. I unplugged it and plugged it back in and now it will not work at all. This particular Sonos Amp will not identify the Arc port no matter what I do. Also, I have tried the other three SONOS Amps and have the same issue with the same TCL TV. I then plug the TCL TV back into the Polk system and low and behold, it works perfectly. I then introduced my Samsung TV and got it to work with one of the Sonos Amps using HDMI Arc. As soon as I disconnected the Samsung TV and installed the TV in its place, I reconnected to HDMI Arc, same issue, Sonos Amp will not identify. Sonos APP says Arc not connected when going through the install process. Settings on Samsung TVs were not changed and have not changed. Also, using same brand new HDMI 2.1 cable. And, once again, to back test, connected the Samsung TV to my Polk system and again it worked perfectly.

I have performed these same exact steps with my Sony TV as well. I have the EXACT SAME OUTCOME. I have also reset all TVs and SONOS Amps to factory settings and have the same issues. Now, tell me this isn’t a Sonos issue. 

@smitty1970,

If not done already, rather than posting to the user-community here, you are probably best to reproduce the issues you mention, where things are not working for you and then immediately submit a Sonos system diagnostic report from within the Sonos App, note all the references and then contact/chat with Sonos Support Staff via this LINK and see what the Staff can perhaps suggest to resolve the matter. I’m not sure the Sonos users here can provide you with any other suggestions to try, you are best to gather the diagnostic evidence and then go check with that Staff if that reveals anything,

I hope you get it sorted.

Thank you. I did not know that was available. you do this through the sonos app?

Yes, if you select the hyperlinks in my previous post you should see the detail of what you need to do. 
Hope that helps.

This happened to me tonight after years of my system working flawlessly. After many attempts to fix, I finally unplugged the Sonos ARC and my Samsung TV for 2 minutes. When I plugged them back in and checked the ARC connection in the Sonos app, it connected and worked again!

My Sonos Arc HDMI port was mysteriously broke down after working for only 3 weeks. I bought it just 3 weeks ago. I had other brands of sound bar and none of them had HDMI port failure. I wonder how many Sonos Arc users have experienced failed HDMI port.

After years of working without issues, my Sony TV Arc combination stopped working. Switched eARC from auto to off in the audio settings of the TV. Doesn't make too much sense but worked.

I was having a similar issue with it suddenly stopping via Arc. Worked via TV speakers and the TV indicated that it could not see the Sonos. Fiddled with swapping cables, turning things off/on, changing any setting I could find and the item that worked for me was on my Apple TV 4K.

All I did was change the output to “temporary” and my Sonos via Airplay which started playing sound(s). I switched back to TV speaker as the Apple TV output and it works just as before. Swapped back to OG cable and it’s flawless. IDK, but I hope it helps someone else sort it.