It seems like this issue goes beyond just your issues. In my current internal build the same issue is appearing when playing the game as a standalone. It is thankfully not an issue in the version currently on the marketplace, but the issue I am seeing seems like the same you are having. Test this to see if you have the same problem:
Add a mesh or any visual component to the turn manager so that it is visible. Place a turn manager actor in the game so you can see it. Use regular play in editor and confirm that it is there. Then play as standalone. If we are having the same issue the turn manager should not appear. It seems like it is deleted before the game even starts and is not allowed to be spawned. It is a very strange issue and I’m working hard on finding a cause.