Product swatches are only displayed on shop page the first time shop page loads

The product variation swatches are displayed only when my page first loads. If I scroll to the second page or click to “Page 2”, the products no longer have variation swatches.

Then when I go back to the first page, the swatches are also missing.

However, if I refresh the page, the swatches show up again.

How can I make keep the swatches always on display on the shop pages?

I only have an internal dev site now so don’t have a URL yet.

Thanks.