URL: https://www.xfinity.com/stream/

Browser / Version: Firefox 140.04
Operating System: Windows 11
Tested Another Browser: Yes Edge

Problem type: Site is not usable
Description: Page not loading correctly
Steps to Reproduce:
While Xfinity Stream page hung on Firefox (constant 3 dot loading screen), the page worked on Edge. I tried the usual Firefox troubleshooting (clearing cache cookies, running in troubleshoot mode, disabling anti-virus, ETP disabling) none of which helped. This only started after the Firefox 140.04 version was installed.

View the screenshot

From webcompat.com with ❤️