Annoying Spell Check Bug (Dark)

Hi all, apologies if this has been answered elsewhere but I can't seem to find a solution (and it's highly annoying!)

When running a spell check, the flagged word is always in a dark box on the interface as shown, making it very difficult to see the issue. I assumed it was potentially an interface issue, so I ran the same on the lighter grey interface but encountered the same issue. A previous colleague had this issue and removed / reinstalled Indd CC which fixed it, but I've done this twice and the issue seems to remain.

Any ideas? Is this just a common bug or is there a way to fix it?

Any help greatly appreciated!

Thanks, Ekke