I inspected the page in Google Chrome and it looks like there are two sets of navigation: nav class="woocommerce-pagination" and <div class="pagination woo-pagination">
It looks like the <nav class= is for numbered html links and the <div class= contains buttons for each page.
It looks like maybe the nav class is vertical when it should be horizontal in order to sit inside of the div class. But the div class seems to be handling all of the navigation by itself.