OpenGround, Data Import, Overwrite with empty values not working

When importing csv file, it does not overwrite the empty cell if I have deleted an item EVEN if/when I select the box: Overwrite with empty values. What am I doing wrong? It updates the other changes to text, if not a deletion or a capitalization change. How do I make the overwrite work & how do I have it update if a capitalization/lowercase changes? Thanks!

Data, Import Data, select: Overwrite with empty values, file format: CSV, Add, file format: CSV, select file, Open, Next...