If the parent event untriggers a nested event while the content playing inside the nested event is inside a transition timeline, the nested event continues to play indefinitely. It seems like the nested event is seen as a one shot event (played entirely while being untriggered), whereas it is a looping event. The workaround is simply to check the “cut” button, or to set an AHDSR on any track’s fader in the nested event.
By the way, I have a suggestion, somewhat related. If the nested event is detected as non-one shot (containing any kind of loop, transition or sustain point), why don’t you hide the “cut” button (or lock it in an activated state), since it doesn’t do anything? It would probably make people less confused.
[FMOD Studio 2.02.00]