Random child actor component

I am making an endless runner and I want to spawn a random obstacle from an array but I’m not sure how. I tried making an array of all my obstacles, which are blueprint classes, and then choose a random one from that array and spawn it but I can’t actually add anything to the array.

My obstacles don’t have a parent. They are separate blueprint classes.

When I use an actor class for the array it spawns a random one but it spawns it in all three possible spawn locations instead of one.

Screenshot - 0fe44ea9d4df4454823c2dc98d386347 - Gyazo Screenshot - c91d938c95b42915f6a5886ae3abb799 - Gyazo