X1 audio is l/r stereo in 5.1 wrapper, no 5.1 audio

Did something change in X1 digital audio output? The XG1v4-A is outputting sound as stereo in a 5.1 wrapper, with only left and right channels available on many X1 channels and all app channels (like Prime, Peacock, Netflix, and AppleTV).  5.1 digital was available for most everything, but disappeared in early January. Have tried both auto and expert 5.1 audio modes and even multiple boxes but no luck. Frustrating to miss out on surround audio for movies, music and even the recent Olympic broadcasts.