I don't know if this happened after the upgrade to latest version or but I swear my drill points were graded after deleting internals months ago. So I did an experiment and imported a piece again and deleted a line connecting the internals. The grading disappeared. So I thought, save the piece into the model and copy/paste the grading to the drill holes. I used to be able to bring a piece in by dragging it but now it will not accept it no matter what I've thought of.
I hope you have a quick solution so I don't have a lot of rework.