Bluetooth headphones no longer working with Xfinity box, but fine when watching Smart TV

I have two smart TV's, each with an Xfinity cable box. For the past year+ I have paired my Bluetooth headphones (Sony and JBL) via the smart TV settings interface, and they both worked fine on either TV.  When I switched TV Input to the Xfinity cable box, my Bluetooth headphones continued to work with no problem.  Starting yesterday, on both TV's and both sets of headphones, I hear "nothing" when TV Input is through Xfinity box, but they work fine when I'm watching something on my smart TV's.  I've reset both sets of headphones and disconnected both cable boxes, but still no luck. Also, there is no option on the Xfinity Settings menu to connect a Bluetooth device, though as I said, the Bluetooth headphones were working fine for 1+ years until yesterday. Thoughts?