Hi I have this problem for a long time. The audio, when I play a sequence in the level sequence editor, is very loud, and when I play the game in simulation the sound seems correct. I checked Sound classes, mixbusses, soundclassmixes and everything have the multiplier to 1.0. Only the Dialogs of the game have the soundclass at 2.0 and it’s the only sound with no difference between level sequencer and ingame sound.
I found another thing, the real-time audio is too loud too. I have to set it to 50% to have the same volume between the viewport and the game. Maybe it’s the problem come from the same source.