Cam 5.2 is meant to be a cytoplasmic stain. Apart from the nuclear halo, it does stain the cytoplasm well and also doesn't give any nuclear staining as expected.
I'm sending you the staining protocol link from BD. Some perinuclear staining could be OK, but the ab is against a cytocheraratin, that should be present mostly in the cellular membrane, so why you expect that it is inside the nuclei?