I think I might have the same issue, was working it's about 15 days old didn't sure it thru the tv for awhile cause I was studying and then today being the 27th of June I noticed it wasn't working through the tv and that the arc seems to have something to do with it. If you find a fix let me know.

*Edit* after remembering it came with an optical adaptor and connecting it.. it's seemed to work.

Why did you use an optical adapter?  If using eARC between TV and Sonos Arc (Arc vs ARC is so confusing and annoying) you should be using an HDMI cable - this is my setup and situation I have, where it is definitely plugged in (bc I can physically observe it AND I’m getting sound via the Arc soundbar lol), but S2 app doesn’t see it / tells me it isn’t.  

You should never connect your ARC via Optical when you have the possibility to connect it via HDMI. The whole ARC doesn't make a lot of sense without Atmos / DD+ or TrueHD. 

I am clearly having issues with the ARC, personally I would rather it just work of course i would wont the best sound but using the optical adaptor thru the htmi seems like my only option… so yea it seems to make sense. If you have a fix @SpiDey1500 I would love to hear it otherwise your just adding 2 cents for nothing. I was tired as well @rparkernyc and must of not read that you still had sound sorry for jumping on your tread. 

Hi @rparkernyc, @SpiDey1500  and @keith_3200, Thanks for reaching out and welcome to the community. Thanks for bringing this up and we understand where you're coming from. Sorry for the delayed response. Regarding your concerns about the Sonos Arc that doesn’t detect the HDMI EArc status after the update on the Sonos App. I’ll ask you to submit a diagnostic report for us to investigate further what could be causing this issue. You may reply to the thread with the confirmation number to assist you with this issue.

Let us know how you get on with the advice above.

We're here to answer any further questions you have.
 

Hi, similar issue here. Just bought Sonos Arc, followed intructions in S2 app but altough it’s properly plugged to HDMI ARC port in my LG oled tv, app still shows an error that the connection has failed. Tried it like 10 times, restarted both tv and app, made a brand new setup using iPad or iPhone, but still the same bad result:(

Can anyone help? Otherwise I’m must return it..

thanks.

Hi @hydronaut, Thank you for reaching out and welcome to the community. Thanks for bringing this up and we understand where you're coming from. About the same concern with your Sonos Arc, I’ll ask you to submit a diagnostic report for us to investigate further what could be causing this issue. You may reply to the thread with the confirmation number to assist you with this issue. So we can check the status fo the Sonos Arc connected to the TV.

Let us know how you get on with the advice above.

We're here to answer any further questions you have.

Helo Simon,

the diagnostic report sent - nr. 2038507686

Thanks for your help.

Hi @hydronaut, thanks for the update. I appreciate you taking the time to submit the diagnostic report. Upon checking the diagnostic report, It only shows a controller diagnostic. which means I’m not able to see the status of the whole Sonos system. Kindly make sure that you’re connected to the correct Wifi name on your mobile phone controller and re-run the diagnostic report. 

Let us know how you get on with the advice above.

We're here to answer any further questions you have.

Hi, new report sent - 1662041824

Thanks.

hi @hydronaut, thanks for the update. I appreciate you taking the time to submit the diagnostic report. Upon checking on the diagnostic information. It shows that the Arc status is disabled. Kindly check the CEC settings on the TV and enable it. Also, try to unplug the HDMi Arc cable from the Sonos Arc and from the TV for 1-2 minutes and replug it back in. 

Let us know how you get on with the advice above.

We're here to answer any further questions you have.

Mystery solved:)

Thank you!

Hi @hydronaut, thanks for the update. I’m glad it worked for you about enabling the CEC on your TV and unplugging and replugging the HDMI Arc cable. 

If there is anything else I can do for you, please, don’t hesitate to let me know.

The Sonos community is always here to help.

I have an LG cx. I just ordered the arc which won’t ship till mid January. After reading this post I’m wondering if I should cancel my order. Do they all have issues with sound dropping and magic remotes not working?  Please be honest. $850 is a lot to spend on a sound bar that only works sometime. Thanks. 

I’m having a similar issue. My LG GX oled recognizes the arc and plays sound through it. However the app says there’s a problem, and my remote cannot change the volume.

I must have plugged/unplugged a dozen times and tried 3 different hdmi cables. The sound is good and is getting an Atmos signal (can see it on my app).

The LG simplink is on. 
what else could it be?
 

Hi @joebpops, Thanks for reaching out, and welcome to the community. thanks for bringing this up. About your concern for LG TV’s with Sonos Arc, there is a firmware update that is being released by LG to have the issues fixed with soundbars. and for the remotes, here's an article about LG Magic remote setup on Sonos. 

Hello there @MattEa, Thanks for reaching out, and welcome to the community, Sorry to hear about this issue with your Sonos Arc on your LG TV, kindly check if there is any pending firmware update on the TV and check if the issue will be fixed. or you may also  submit a diagnostic report for us to investigate further what could be causing this issue

Let us know how it goes and we're here to answer any further questions you have.

Hi Simon. 

Thanks for the reply. I have done the most recent firmware update. Most say it does not solve the issue unless lg has another one on the way. I find it difficult to determine if it’s an issue with the tv or the sound bar. I’m waiting to see how this all plays out before making a final decision. I did cancel my order but if this all works out I’ll pick up an arc at best buy. I feel it would be easier to return if needed. Let me know if you expect another update from lg and possible timeframe for that. Thanks again. 

Hi Simon,

Yes. I have checked for a TV firmware update and am running the latest version. 
 

This is my diagnostic report number: 551452744

Cheers,

matt 

Hi @MattEa, thanks for the update and for sending a diagnostic report of your Sonos system, upon checking, it’s odd that it doesn’t detect that the CEC or the Simplink is enabled on your TV. We’ll take this further, I'll ask you to kindly contact our phone support team for further assistance and more in-depth troubleshooting steps. They may ask for additional troubleshooting steps and give you options about this issue. 

Let us know how it goes and we're here to answer any further questions you have.

Hi, I'm having the same exact issue with my LG CX OLED. The eARC connection was working fine for the first month, then it stopped randomly. I changed out the HDMI cable and it worked fine again for a couple of weeks. Tonight it died again. 

I tested three different cables, reset my entire system (all power off for 60 seconds), and unplugged the HDMI cable for several minutes, checked the TV for updates. The app says the eArc is not connected.

Simplink is on. Sound is coming through all of the speakers (although I don't know how to check if it's receiving a proper ATMOS signal) but I can't change the volume through my TV remote.

I sent a diagnostic report: #642793283

I super appreciate any help with this. I super don't want return this system because it sounds wonderful and I really love it.

Thank you

Hi @dbrian56, Thanks for reaching out, and welcome to the community. Sorry for what happened to your system and thanks for sending a diagnostic report of your Sonos system. Upon checking, It shows that the CEC or Simplink is disabled on the diagnostic report. But If you’ve already enabled it and still having issues with the EArc not connected. We’ll take this further, I'll ask you to kindly contact our phone support team for further assistance and more in-depth troubleshooting steps. They may request remote access or screen share with your device controller and ask for additional troubleshooting steps and provide other options in resolving this issue. 

Keep us posted on how it goes and we're here to answer any further questions you have.