Same issue on PMS 1.16.1.1291 and the last 3 releases (at least) on Win10 1890 64bit. Casting to chromecast ultra randomly stops after and intermittent amount of time. Skipping to the next/previous track does get it playing again. Other devices seem to work fine.
Also, plex randomly moves to the next track in the middle of the current track. This happens on all devices; chromecast, android, web, etc.
Playback on my family’s two android phones crackles constantly without fail.
I thought the removal of plugins and other functionality last year was designed to allow the team to focus on core functionality. I have a lot of issues just playing my content. Nothing special.
Plex team, from one developer to another, please focus on QA of your core functions. Without a solid base, everything you build on top of it will be flawed.