Cannot connect to Cast devices from PlexAmp

Connecting to Cast Devices (Google Nest Mini, Google Nest Hub Max, Chromecast) simply does not work with Plexamp on my Pixel 3 running Android 11.

I can cast from any other app just fine, but plex simply does not work. When I try to connect, the loading spinner just spins, and eventually disappears.

On a device with a display (Chromecast/Nest Hub), I get a Plex screen saying “Sorry! Something went wrong”. Speakers make the sound that something was connected, but media never begins playback.

I’m still having this issue, on version 3.4.4. I can cast from every other app just fine, even Plex. Only Plexamp has this issue.