W2S – Product Images will not migrate

Hi, I am working with the importer and most detail appears to be crossing into shopify however the images will not sync. It is showing no error and says the job is complete however it will not send the images across to the shopify listing. If we manually add a product image in shopify then try and sync the product again it then deletes the image.. Are you able to advise on why and how to send the product images across.?