I'm glad you mention that. When I first started testing I could have sworn it was only Apple TV+ that was out of sync. Amazon Prime and HBO Max seemed fine and I actually created a bug report with Apple stating such. But now I swear that everything is out of sync.Yeah I’ve had sync issues, you’re not alone. Hopefully get fixed.
Oddly, Disney+ content is in sync with my AirPods Max, but Apple TV+ is not in sync.
It's understandable that there would be some kinks with the beta and new tech. I just hope it's reproducible on their end and it can be fixed as it sounds great otherwise. As someone who lives with shared walls, I've been looking for a TV headphone experience like this for a long time.