Thanks for the the info.
Ok, so for some reason it works as expected in some of my own basic missions, and in some it doesn't. I get the issue in multiplayer server i tend to use, so that would rule out my world having a bug, i would think.
That said, it happens on this one. i tune the radio, and then open up mission resources menu and immediately the radio goes out, but never comes back. You don't see the menu window open up on the track, but it is at the moment the music goes off.
i've included two tracks to the op, one where it works the other where it doesn't