Hello,

Please follow the instruction above thoroughly and your thumbnails gallery would have 2 rows and 4 columns, like this: https://monosnap.com/file/1UUCxaYDEjLr7pyut10lX6vTqicm5T

You need to do two things:

1. Please enable this option: https://monosnap.com/file/feXObPSZ6aKe4nZ1ZuZFltqmgaoort

2. Please add this code to the Theme Settings > Custom CSS > Desktop:

.product-image-summary .thumbs-position-bottom_grid .product-image-wrap:not(:first-child) {
    max-width: 25%;
    flex-basis: 25%;
}

Best Regards