Your primary category is the right one
Of the 187 factors Whitespark's 2026 study scored, primary category came out number one for the map pack. Not in the top ten. Number one.
Most businesses pick something close enough and never revisit it. "Contractor" instead of "Roofing contractor". "Plumber" instead of "Drainage service". Go look at the top three results for the search you want to win and check what they've chosen.
Score 0 if you can't remember what you picked, or you picked it in 2019.