Hello,
LQIP loading uses another preview images than the thumbnail size, it uses 10x10px images. If you switch from Lazy loading to LQIP then install Regenerate thumbnails plugin and regenerate thumbnails for all the images you have to generate 10×10 preview images.
If LQIP or Lazy loading do not suit your needs you can disable optimization loading and load default thumbnails for your images that you set in Media settings or in Theme Options > WooCommerce > Product images (depending on type of element that you use: products or posts).
Regards