If a custom attribute is not showing as a column on the sheet, the solution is to go to the Settings > Advanced Settings > WooCommerce Products > Custom Attribute Names > Enter the name of the missing attribute. You can enter multiple names separated with commas.
Also, this works for creating columns for new custom attributes.
Note: If the attribute still doesn’t show, go to settings > scan DB and do this 2 or 3 times so the sheet recognizes the new fields.
