Some actors move some do not

I’m not sure where to put this but I have a weird issue I just can’t seem to figure out what is going on.

I have a large landscape with a Navmesh + Postprocess volume which cover the entire landmass (above and below). I have been putting a SpawningBP around on the map and when I go to play only some of the spawned actors are moving around. All the actors are performing their idle animations, and when hit register and give damage to the player actor. But some of the SpawningBPs spawned actors just won’t move.
Any help would be greatly appreciated as I am completely stuck as to why this is happening. I can’t seem to find any common factor (in fact they are all just duplicated from the first one) in the ones which do not move to those that do.