Ok so here’s some more info to digest:
First I changed the call to Run() to execute in the Tick() function. Then I put the first thread to sleep for 20 seconds. Lastly I used an AddOnScreenDebugMessage() to BeginPlay()
Results:
The whole game is paused until Sleep(20) has run it’s course. The debug message in BeginPlay() doesn’t display until the sleep has run it’s course and the threads are still running first to last.