What version of the Plex app and on what device?
There was an old bug, but it was fixed four years ago in Plex for Android 7.11.
Other than the Chromecast are any other real devices listed?
Like Tom, trying to replicate, but cannot. I see my Shield, but no Sonos devices listed.
Running Plex for Android 9.15.0.38108 on a Pixel 6a.
