Show the issue and provide steps to replicate.

website www.xfinity.com/stream/ will replicate the problem

website www.xfinity.com/stream/ will replicate the problem

It would be helpful if you post a screenshot of what you're seeing. Let me see...

Here's what I get. see screenshot Let me turn off a few things because Comcast is a painful site with Firefox. Just paying the bill I have to go into Troubleshoot mode to get it done.

I'm on Linux and no go for me. I opened a ticket on Github for this issue. https://webcompat.com/issues/166738 Let me go see what happens in Windows.

Works fine for me in Win11. see screenshot Did you try Troubleshoot Mode? https://support.mozilla.org/en-US/kb/diagnose-firefox-issues-using-troubleshoot-mode#w_how-to-start-firefox-in-4troubleshoot-modesf5safe-modesf

The attached file shows the sequence of operations which used to work on Firefox (prior to last week) and presently works on Microsoft Edge.

Did you try Troubleshoot Mode? https://support.mozilla.org/en-US/kb/diagnose-firefox-issues-using-troubleshoot-mode#w_how-to-start-firefox-in-4troubleshoot-modesf5safe-modesf