I have a Sony XR-65X90CJ, Playbar/5.1 setup, Xfinity X1 cable box with the XR15 V2 UQ remote. I am using the S2 app and system as of now.   I have set up the XR15 remote as the remote for the Sonos system, but it is not working correctly.  And now, in the S2 app, I can’t even find the place where I originally set up the remote (this link: https://support.sonos.com/en-us/article/control-sonos-home-theater-with-your-tv-remote - does not match what I see in my S2 app).   So 1) I can’t seem to disconnect the remote and try again.  2) FYI - I am connected via optical, set to PCM (which on this TV is always fixed).  I have the TV output set to max. The TV speaker are off and the output is set to home theater.

When I lower or raise the volume on the TV using the Xfinity - the numbers on the TV go up and down - sometimes it changes the volume, sometimes not.  I often have to go into the Sonos app and use the volume slider which also responds in odd increments and weirdly out of synch with the numbers on the screen.  It seems as though the systems are competing. Another symptom is that the mute function is out of sync.  Sometimes the TV will show Mute when sound is coming out and other times it gets out of synch with the mute. 

I’ve read everything I can find here and have yet to find why this is not working. 

I had this problem earlier with a previous Sony Bravia 850 and the S1 and was able to sort it out, but when I upgraded to this TV and a new cable box, I had to re set the whole system and the above description is the result.

Be nice to even be able to find how to forget this XFinity remote and try again! 

Ideas appreciated.