Checkbokser vises gjennom stickyheader

### Description of the bug

I en tabell som bruker stickyheader og har vertikale checkbokser med mange alternativer så vil boksene vises gjennom headeren slik vist i bildet.
Det er samme tilfellet for radioknapper.

### Steps To Reproduce

Se over

### Additional Information


Start by reproducing the issue in a table with a sticky header and many vertically arranged checkboxes, using the attached image as the visual reference. Inspect the table header and checkbox/radio rendering paths; done means neither checkboxes nor radio buttons show through the sticky header.

Written by the indexing model from the issue text.