plexmediaplayer.list contains: deb https://downloads.plex.tv/repo/deb/ public main but I get the below message every update.
Full message when running sudo apt-get update:
W: Conflicting distribution: https://downloads.plex.tv/repo/deb public InRelease (expected public but got )
I'm not sure if it's not working or not as my currently installed version matches the latest public release however this notice only recently cropped up for me.