...if you click on a portrait in combat.
Repro:
1. Enter a combat, notice that a combat music starts
2. Click on a unit portrait on the left side (I clicked on my sovereign/champ.)
Observe that:
1. combat music cuts off immediately like you were just in strategic view
2. and won't resume after exiting the char sheet view
Note: using Sound Blaster X-Fi, in game setup: Dolby 5.1