In Unity/Wwise -
I have simplified this issue to about as basic an implementation as you could ask for: Single soundbank, always loaded. No streaming. All instance limiting removed on sound objects and busses. Events just calling to play a music playlist directly. However, when I load into a level, I consistently get the Event triggering, and in the same frame, "finishing" before the music ever has a chance to play.
I have tried this in 2019.1.6, 2018.1.10, and 2017.2.4, with the same thing on all of them.
What is bewildering is that in SOME scenes, I do the exact same procedure and the music plays consistently. But in other scenes, I get this behavior consistently.