Mobile – Remove Lazy Load Effect?

I don’t see any lazy load script on your page. I think the effect you are seeing is the phone’s GPU having trouble displaying images fast enough. Yes, you’ve fiddled with image compression so the byte size of images are reasonable, but they are still way oversized images for most mobile devices. The GPU must resize images that are a few thousand pixels across to the mere few hundred pixels of a phone screen.

Your images do not have srcset and sizes attributes that would let devices fetch images that are closer to what they need in pixel size. Ideally, each uploaded image would have a number of pixel size versions that are listed in these attributes. Normally, img tags in post and page content are passed through wp_image_add_srcset_and_sizes() in order to add these attributes. For whatever reason, this is not happening with your images. It might have to do with how the content is generated.

The image attributes do need to have a reasonable selection of image sizes to choose from. If your media library is not creating appropriate image sizes, use add_image_size() to register appropriate sizes. Then if the img tags are run through wp_image_add_srcset_and_sizes() before output, phones can utilize appropriately sized images instead of needing to resize very large images.