Hello, I'm trying to create a homebrew item that gives me armor bonus, spell attack and dc bonus - so far so good, those worked fine - and a half-proficiency bonus (rounded down) to some of my saves. This last part is not working.

Can someone point me where I'm mistaken? I just found old threads about this issue, so I don't know if its corrected or not.

This is how I'm trying to set up de bonus:

You’re not doing anything wrong, if it’s not working it’s because it just doesn’t work. Not everything does.