It seems like one of the more recent Plex Pass versions of PMP (last month or so) has broken the ability of Plexamp to control track selection on a remote PMP. Was working for me for about two months (after a UI fix I brought up was released). Was hoping the 1.0.5 release today would fix this issue, but no luck.
Running Plexamp 1.0.5 — did a completely fresh install, trashing all prefs and support files
PMP 2.8.0.813-6e77dc0c — running on remote server
Plex Server — 1.12.2.4929 — was on the Plex Pass beta channel, but downgraded in case that was the issue here
Problem — Selecting a track or album to play has no affect on currently playing music, and fails to start music if it’s not playing already.
I should say, I can play/pause the current track, and go to the next track.
If I had to guess, I’d say some recent playlist feature in PMP is breaking this. I’ve notice PMP now gives me a nag screen asking if I want to replace the current playlist when something is already playing.
Really love the idea of this, and it was great when working briefly, but have spent a bit more time debugging Plexamp than actually using it. I realize remote control / playback is probably an edgecase for you, but definitely my primary reason for me a Plex subscriber.