Background Audio not working on iOS 15 (Xfinity Stream)

I have the same background playback problem that is mentioned in this and other threads.  I followed all the instructions to uninstall, reinstall, reboot, and check settings-preferences.  I have Xfinity Stream 7.6.0.xxx and iOS 15.6.1.  I do not have an “allow background audio” option under playback preferences.  Same issues on WiFi and/or Cellular. 

However, I did stumble upon a workaround: once I have the XF Streaming app running I leave the app (losing audio), press and hold the Power/Siri button, leave Siri, and hit play on the iOS Quick Menu panel (swipe down from top right)…The audio plays in the background for me.   Good luck!