catalog\view\theme\royal\js\common.js
if (cols == 2) {
$('#content .product-list').attr('class', 'product-layout product-grid col-lg-6 col-md-6 col-sm-12 col-xs-12');
} else if (cols == 1) {
$('#content .product-list').attr('class', 'product-layout product-grid col-lg-4 col-md-4 col-sm-6 col-xs-12');
} else {
$('#content .product-list').attr('class', 'product-layout product-grid col-lg-3 col-md-3 col-sm-6 col-xs-12');
}
заменить на
if (cols == 2) {
$('#content .product-list').attr('class', 'product-layout product-grid col-lg-6 col-md-6 col-sm-12 col-xs-6');
} else if (cols == 1) {
$('#content .product-list').attr('class', 'product-layout product-grid col-lg-4 col-md-4 col-sm-6 col-xs-6');
} else {
$('#content .product-list').attr('class', 'product-layout product-grid col-lg-3 col-md-3 col-sm-6 col-xs-6');
}