How do you sync two ambient audio cues?

I’m trying to sync 3 Soundtrack WAVs as well. (Fading between them)
But Even if I start them all in one CUE at the same time, they are out of sync to begin with and keep going out of sunc more and more. This happens on PC and in iOS (iPhone6).

Is there ANY way to sync those 3 audio loops?
Thank you!

Attached is an image of my CUE setup.