No sound once actual movie starts

[CM1014]

Not sure where to place this question but really hoping someone can help because it’s driving me nuts. I have Sony X930E tv, Sony UBP-X800 Blu Ray player and Polk MagniFi soundbar that runs through the tv. I never had issues with the soundbar until I upgraded to 4K. Now, every once in awhile I’ll play a movie and there will be no sound. Interstellar for example or Planet Earth play sound during the main menu screen but once I start the actual movie it goes silent. Some movies work completely fine. I’m not an expert with this stuff so I have no idea what this could be. Just got Deadpool 2 and the movie plays sound but the main menu screen is silent. I don’t understand what’s going on.

Does anyone have any suggestions on what could be causing his issue? No sound issues when watching normal tv which makes me think it’s the blu ray player but it’s weird to me that some movies work fine. Any help would be greatly appreciated.