After getting another bout of the “timestamps and assets map are not in sync” error, the music in the game I’m working on no longer plays, although sound effects still work. The problem has persisted even after going through the rigamarole needed to fix the timestamps-assets map problem (including a full reimport of all assets), and also putting in a new audiosource for the music and checking that the audio file still works (it plays fine in other software).
I’m hoping someone else has come across this problem before and knows how to fix it.
If anyone else has a similar problem: although I haven’t found a cause, I did find that the effect was limited only to one script (which happened to be my GameManager script, unfortunately). The audio on instantiated explosions still worked even when the audio file was switched to the theme song, so I “solved” the problem by instantiating a prefab which just contained an audiosource with the theme song, set to play on awake, then I had GameManager instantiate it at its own position. Not a great solution, but it works.