As a workaround if you're using one of these TVs, you can set the output of the TV to PCM (Stereo). There isn't any issue currently with that TV streaming stereo content to the PLAYBAR through the optical. Otherwise, you can look into using a different device. Some suggestions for setups and community recommended devices can be found here on our megathread.
We are working with Samsung on this issue, but there isn't currently a timeframe for a resolution. We'll update you as soon as there are any further details.
Because of the nature of this issue, we've added these televisions to our PLAYBAR Compatibility page which can be found here.
Best answer by Ryan S
We've been testing the firmware of these TVs with some of you and have verified that the Dolby handling issues of the past with these TVs have come back as of software version 1510. We're going to work with Samsung to see about sorting out the issue, but we've been able to replicate the cut out issues on both Sonos hardware and other soundbars too. The PLAYBAR has gotten better at handling poor audio signals in recent updates, so this issue is less noticeable than before, but it's happening.
You can verify the installed firmware version by pressing the MENU/123 button on the remote, then selecting Menu, Support, and then highlight Software Update.
For workarounds, while they sort out the firmware, you can either bypass the audio coming from those JS/JU model TVs by plugging your Sonos directly into the source, or an HDMI switcher, or go into the TV settings and set the audio format to PCM instead of Dolby Digital.
I'll let you know here when we've gotten confirmation that the software has been updated.