Unable to place cut copper top half slabs

I am unable to place cut copper top half slabs. As far as I can tell, it is only cut copper that is acting like this. I have tried placing from the bottom of a higher block and from the top part of the side face. They WILL place on top of bottom half slabs. No variation of cut copper slab will place on the top half. I don’t know if this is important but it doesn’t work on either creative or survival.