Could not remove parent categories

Hi, I have created a bunch of categories using bulk WC category Creator and deleted all categories in woocommerce, however, there are a bunch of categories showing up in the parent category dropdown menu when I was trying to add a new category! I am not sure how to remove them..! It’s really confusing me. Those parent categories which are showing up in the dropdown menu are not listed in the category list. Appreciate your quick response – Thanks