Another bug in the Tidal/Plex interface. If you add a multi disc album to Plex music from Tidal, the track order on the discs past number one all get screwed up. You can click to play a song and it plays something totally different. It only seems to happen after the disc has been added to the Plex DB, if you play the album direct from Tidal through Plex all is okay.
If you’re still looking for a ‘solution’ to this, I have worked out that you can get around it by adding all the songs of the albums individually. Painful, but it works.