Just found this thread after having the same issue - am not new to Unreal and Audio, but I am new to Unreal Audio!
Would turning off the One Shot option not mean the sound effectively plays forever?
I am effectively using it to call a one shot sound, but its a long sound, and the player can be out of range when it triggers, then move into it within its duration. Is it safe to use this workaround, or could I be left with loads of instances of the sound permanently hanging around?