Private listening stopped working with the Roku Media Player after FW update, but not with all videos. It may have to do with specific codecs. Most videos in my media library which used to work will no longer play audio.
I have tried with my RC-AL4 remote and with the Roku app on my smartphone, but the same videos are silent.
I have a Roku Ultra 4660x.
It seems the May 12th, 2021 update broke it.
(Also having the stuttering noise problem on files which used to play fine)