Product thumbnail poor quality

Hi,

You need to increase the sizes you have set in Appearance > Customize > Woocommerce > Product Image.
https://gyazo.com/1b45d5e0222e85a7636ad1e0d0f4e963
Please check this manual:

https://xtemos.com/docs-topic/image-size-and-content-alignment-in-a-product-grid/

Basically the product images are controlled by woocommerce and our theme doesn’t influence this.

for some reason your blurry images issue continues, it could be due to, Your image size settings are too small. Original images need to be of a higher resolution. Your image dimensions should match or be higher than those of your theme.
https://woocommerce.com/document/fixing-blurry-product-images/

Best Regards.