A few months ago, I converted a spreadsheet from OpenOffice to LibreOffice. At the time, some cells had comments. I’ve since noticed that any cells that contained comments in the OpenOffice sheet can be deleted, but the little red indicator in the cell won’t disappear. It works fine for any comments added and deleted now, but the cells where there were comments during the conversion will not go away.
Even if I do a “delete all” on the cell, the contents and formatting and everything else goes away but the red dot remains. Frustrating.