There's 2 ways I can manifest this issue:
First way, starting from Poweramp music screen, trying to change playlists. Press top left to go back to Playlists. Select new playlist, then select song in new playlist. Screen goes back to AA Poweramp screen, but the song doesn't change; it's the same song that was already playing and nothing happens.
Second way, just changing songs within a playlist. From AA Poweramp screen, select bottom left option to see the queue. Select a new song, but nothing happens. It goes back to the AA Poweramp screen with the old song still playing. Song does not change.
I reverted back to 838 and issue is gone and it works fine.