Cut copper slabs cannot be placed on the upper half of blocks

Extremely weird issue where copper slabs simply cannot be placed on the upper half of blocks anymore like other slabs can. Used to work without issue, now suddenly completely broken, severely limiting the use of copper in builds.

Video of error occurring, video file too large to share here: https://youtu.be/MCcCm5ak-Ms

I'm at a loss for how this even broke, given it worked just fine before.