Exact same problem here... only on my own created stations. 1-2 songs maximum, then stops. This has only been happening since 11.3.
While we're at it, how come we can't do the infinity thing on stations we can do on our own playlists (to make it keep going with similar music forever)?
I do not think I am in the minority: I use Music all day at work as background, and it has become terrible for doing that. I wish we could bring back the ability to continually add songs to a station so you end up with more stuff you like... something Spotify used to let us do (I don't know if it still does, but I may have to go back there to find out).
iTunes got to be a hot mess at the end, but I'd go back to it over Music (especially on MacOS) if I could, as it gave you much more control......