OceanWP Portfolio Category Links Go to 404 Page Not Found

I already asked about one problem with the portfolio extension, but I just discovered another: category links aren’t working.

When I view the portfolio page and click the categories, all I get is a 404 page not found notice.

I purchased this extension and it’s not working.

You can see the various versions of things on the other post.

The page I need help with: [log in to see the link]