Procedural mesh Collision issue HELP

Hey guys. So I am having a weird issue with my procedural mesh as it keep falling through the world like it has no collision. The weird thing is that collision works perfectly for one mesh. As soon as I change the static mesh from which the procedural is made it stops working. Kind of hard to explain so I have attached a short clip showing whats happening. I would greatly appreciate any help. I dont know why this is happening. The only thing I changed in the blueprint is the static mesh.