When switching between soundsets in the Online Master interface - i.e., choosing a Mood in a new soundset (whether one has stopped all previous moods or not seems to make no different - the volume of the newly selected mood is extremely loud, often much louder of than any other sound source played before it. I’m not 100% sure but it looks like sometimes the system decides to maximise the volume of everything: all the individual elements, and the Master’s level, and possible the Minion’s level as well.
My ears are still ringing!
I ran into this bug earlier this evening, though it happened just with a campfire sound, which was unpleasant but not painful. However, just before now I played “Weiralai Battle” in the “TTT Under Iris Hill” soundset, and it was pretty painful on the ears (had to get my headphones off fast).