Hello,
1) Settings > Permalinks > check if you use the Post name type and re-save permalinks. Try after that.
2) Theme Options > WooCommerce > Shop elements > Categories > Open Product Categories Widget By Default > Off
3) Add the next code in Theme Options > Theme custom CSS:
.widget_product_categories.sidebar-widget ul li a, .sidebar-widget ul li a {
font-size: 16px !important;
font-weight: 500;
}
Regards