Oh! It’s odd that Adjust Volume is doing that. It’s working as expected on my end when I call the same handle in different locations - might’ve been something fixed in a later version / a blip fixed by restarting the Editor?
(It admittedly might be worth trying the FadeIn / FadeOut functions directly or the Audio Modulation plugin if the repeated calls to SetVolumeMultiplier are giving grief - they’re a bit more battletested.).