Maybe this should be added as a note somewhere ... as a way to use a different column name ...
Keepass has a function called XML Replace under Tools > Database Tools. It's documented at https://keepass.info/help/v2/xml_replace.html#delstr . To delete a field called Have I Been Pwned, use this in XML Replace ... //Entry/String[Key='Have I Been Pwned'] and under "Action", specify Remove Node.
Then, under Tools > HIBP Offline Check, you can use a different name for the column (I use HIBP Offline). You'd then have to rerun HIBP Offline to populate the new field.