Hello there fritz118,
Thanks for posting in the Apple Support Communities.
Check out the suggestions below to see if adjusting your audio settings will help to clear this up as you're noticing that your soundbar is continuing to connect and disconnect. You can find more information via the following resource as well: Adjust video and audio settings on Apple TV
You can fine-tune the video or audio calibration on your TV, home theater, or wireless speakers, using any of the calibration tools provided in Settings.
Adjust other audio settings
1. Open Settings 
on Apple TV.
2. Go to Video and Audio.
3. Navigate to Calibration, then do any of the following:
• Color Balance: Select to measure and adjust the color of your picture using an iPhone with Face ID and iOS 14.5 or later.
• Wireless Audio Sync: Select to run a test with your iPhone to sync the sound of your wireless speakers to your wired speakers. See Calibrate audio between your wired and wireless speakers.
• Zoom and Overscan: Select to see a reference image you can adjust using your TV’s picture settings.
• Color Bars: Select to see a reference color bar image you can adjust using your TV’s picture settings.
If that isn't helpful, you may need to check additional settings via your TV to see if you can set your soundbar as the designated audio output.
Have a great day!
