Diagnosis
This is a known handshake issue with the TV's audio decoder, particularly when processing Dolby Digital or Dolby Digital Plus audio streams from external devices or apps.
How to Fix It
Change the Digital Audio Out format. Go to Settings > Display & Sound > Audio Output > Digital Audio Out. Switch it from 'Auto 1' to 'PCM'. This forces the TV to decode all audio itself and send it as a simpler PCM signal.
If That Didn't Work
If you're using an external sound system, the issue might be with the sound system's processing. Bypass it temporarily by using the TV's speakers alone to see if the cutouts stop. If they do, the issue is downstream.
Heads Up
Setting 'Digital Audio Out' to 'PCM' may limit the audio format to stereo for some external devices if you're using an optical cable. For ARC/eARC, it's usually fine.