Big Bang Theory

There is no sound for the Big Bang Theory on any of our TVs when we stream Big Bang Theory  on Max. There is sound for recordings but when we go to Episodes and go to an episode and choose Max it’s silent. I’ve tried changing audio on settings but when I do that we have sound for Big Bang on Max and no sound when we watch live TV. I’ve gone over settings on TV remotes but nothing helps. I suspect this is a Max issue since Max is mainly crappy to stream since it was created. Is there anything that Xfinity can do about this or am I just at the mercy of Xfinity and Max while paying for live TV and a Max on my bill?