I am able to fill in all the other fields on the post product page except for the ones in the category section. I am on windows 10, firefox, all updated. I am just going to post the product for sale without that info filled out for now.
@Malissa once your product is published and visible in your backend, are you able to add the category to it?
Yes, I was able to edit the category details from the backend and add the info. It also seems to be working now on the post product page.