Hello,
Add the next code in Theme Options > Theme custom CSS > Mobile:
.row-count-4 .product-category:nth-child(2n+1) {
clear: none !important;
}
.products-grid .product-category {
width: 33.33%!important;
}
.row-count-4 .product-category:nth-child(3n+1) {
clear: both !important;
}
Regards