Marketpress thumbnail images not showing on products page

On my multisite when we upload a featured image into a product, the thumbnail often doesn't show in the /products page on the front end.

If we add the product to cart, the image still doesn't show.

However the image has been uploaded to featured image and shows in the single product.

When I look in the media library the images that don't show on the front end all say "Auto Draft" instead of showing the post it's attached to.

I've tried:
1. Go into product and re-save
2. Remove featured image and re-assign

There doesn't seem to be any pattern to which ones show & which don't... well none that I can see.
You can see an example here:

Any help on this is greatly appreciated!