Hi @blitz143, thank you for reaching out, and welcome to the Sonos community. I appreciate you for bringing this concern to us. Let me help you out.

Let me suggest the following steps to isolate the issue and see if this would work for you

1. Unplug the HDMI cable from the Sonos Arc and the Sony TV. 
2. Unplug the power cable from your Sony TV, the Sonos Arc, and any connected audio source (such as a cable box or video game console). Wait 30 seconds before you plug them back in.
2. Reconnect the HDMI cable to your Sony TV and the Sonos Arc. Inspect the HDMI cable to ensure it’s not bent or kinked and check to see that it’s fully inserted into both devices.
3. Update the TV’s software (if available).
4. Disable eARC on the Sony TV.
5. Adjust the group audio delay. Settings > System > Tap your Sonos Beam > Group Audio Delay and then choose a delay option.

Let us know how you get on with the advice above and run a diagnostic report. Kindly include the confirmation number in your response for us to check. 

If you have any questions about this. We and the community are always here to help.

Hi @blitz143, you're not alone! https://en.community.sonos.com/home-theater-228993/arc-tv-sound-cuts-in-and-out-6842963

I have the exact same setup as you, the only way I can avoid the sound cuts is to disable the eARC feature on the TV for now.

Hi @Rowena B. I did all the settings as above. For the Group Audio Delay, on the Sonos App, I only see it as Low, Medium, High and Max. Which setting should I select?

I’ll send a diagnostic report to you but so far today I have not had any issues since I switched to PCM audio output. I have reverted back to default output on tv and turned of eARC. If the problem persists, I will reply to this message.

@Rowena B. The Diagnostic confirmation number is 942497990

Hi @blitz143, thank you for your response and for submitting the diagnostic. Upon checking, your Sonos Arc is not getting a signal from your Sony TV. We really appreciate the time and effort you've spent on performing the troubleshooting steps that we provided. However, the issue still persists.

It would be best for you to continue working with us over the phone to expedite the process. I recommend contacting our Sonos Customer Care support to perform in-depth troubleshooting and to do some tests on the Sonos app to isolate the issue to provide the best option for you. Please feel free to reach out in the future if you have any other questions. You're always welcome here.

Hi Rowena @Rowena B. I’m not understanding what you are saying. My Sonos arc is working with the TV which means the Arc is getting a signal from my Sony XH90 TV. The problem is that it cuts out every now and then when I’m watching on Netflix. Then I have to restart the TV and Sonos Arc fully for it to work. 

Hi @blitz143, thank you for your quick response. The diagnostic gives us a snapshot of your Sonos system and we checked what we saw in the report. I'm glad that your Arc is getting a signal from your TV. My apologies for the confusion. As per checking further, this issue has been reported to us and you can check this thread for your reference. 

Based on the troubleshooting we provided in this thread, you mentioned that you haven't encountered an issue when you changed the audio output to PCM. You can have this set up in the meantime while our engineers are working on resolving the issue. We apologize for the inconvenience and we greatly appreciate your patience. We'll keep you posted here once an update is available for the fix. 

If you need help with any other information, please be sure to let us know.

I have The same problem i think i will return back my sonos arc 

i am very sad of that situation its is my first Time i bought sonos product and its was my last time

i dont want put my tv x900h on arc mode,  i want listen The best sound with The Earc mode 

I’m having the same issue. I just submitted a diagnostic report (196664516).

Hi folks, thanks for reaching out to the Sonos community and for letting us know about your concern. Have you performed the steps recommended in this thread? If after doing all the steps and the issue is not resolved, it would be best to contact our technical support team for more in-depth troubleshooting steps. Please do not hesitate to reach out if you have further questions or concerns. We are always happy to help out.

@Rowena B. Yes, I’ve tried the steps above and still reproduceable. The thread is over a month old, is there no fix in place yet that we have to spend additional time to contact technical support for more troubleshooting? it seems ridiculous for a $1500+ system to be having these issues.

I am having the same issue with my Sony Bravia. It has now gotten to the point where I need to switch eArc from auto to off every time I turn on the TV. This just started a few days ago after having everything run fine for a year. Please help!

I am also having the same issue, and have tried the same steps to resolve the issue. This is a new system and setup, I have had my sonos and tv setup for a few weeks now. I can’t use PCM because when I use Plex, DTS content doesn’t work!

Any hell would be greatly appreciated!

@w0den Can Plex convert DTS audio to PCM? The Arc now supports multichannel LPCM audio.

I have the sony XBR-65X900H and I am having similar issues with the sound going off.  I tried DD, and PCM and it continues to be caught off.  Is there any news on how to get the Arch to work as it was intended using DD+?

I’m still having the cut out happen for me. The only difference is my TV is a LG. 

Hi, 
I found a workaround in Redit for the audio cut off issue between Sony TV and soundbar (various brand). My friend who own a Sony TV X80H and LG soundbar able to solve the audio cut out issue by using the workaround suggested in Redit.
 
I also own a Sony TV X90H but don’t have a Sonos Arc yet, so can’t test it.
I’m in the middle of thinking to buy a Sonos Arc but this audio drop off issue make me worry.
Hope anyone of you can try this workaround and let me know if it fix for you. 

Workaround as below: 
“Go into your TV's settings and turn off everything WiFi-related. That includes the WiFi radios, the WiFi-related location services, WiFi-Direct, etc. Everything.

Use a hard-wired Ethernet cable to connect your TV to your network.

Reboot (most likely optional).”
Credit from:
https://www.reddit.com/r/bravia/comments/m42k87/potential_fix_for_sporadic_audio_dropout_issues/