marketpress featured product image

Dear Support,

We use AllImport to import our products from CSV files. The import is working fine, we also have custom post types. When we import the images from external url, the files are downloaded and placed successful in the media library. For the selected product we can view the product image on the CMS backend admin area. But on the FRONTED, the first image for the product doesn't shows. When we press updatefor the selected product on the admin, then the image is displayed at the Fronted.
How can we reach that after the import all images is displayed without admin product update. We have 3.000 product, so thats is important for us.

Kind Regards,
David