Everytime I see a while loop in BP, it give me chills.
Cut the wire between the branch and the while node and see what happens.
Are you sure the problem is in this bp? Try creating a new TileGen BP.
Avoid the bottom node unless you really know the expected result of operation.
I see you improved your recursive infinite loop code.
Could you write what you are trying to do?
Probably that stuff can be done with for_loop (or two) and in construction blueprints.