I just followed this. I can get audio playback when I first run Plexamp, but nothing after I stop it, and set it to launch automatically. I still have audio with every other source I try on the device. I’ve tried setting every output option from the playback menu in Plexamp. It seems like something breaks at that final step. I’m on Pi OS Bullseye, fully updated as of this writing. Using Bluetooth audio output.