Hello,
Try to add the next custom CSS code in Theme Options > Theme custom CSS > Global:
@media (max-width: 768px) {
.col-sm-6.product {
width: 33.33333333% !important;
}
body .row-count-3 .product:nth-child(2n+1) {
clear:none !important;
}
}
@media only screen and (max-width: 320px) {
.products-grid .product {
width: 33.33333333% !important;
}
}
Regards