Hello,
1) Add this code in Theme Options > Theme Custom CSS:
.widget_product_categories .children, .widget_product_categories .open-this { display: none !important; }
2) Either go to Plugins > disable WooCommerce Infinite Scroll and Ajax Pagination plugin or set correct selectors according to theme docs https://xstore.helpscoutdocs.com/article/65-woocommerce-infinite-scroll-and-ajax-pagination-settings
Regards
