When a product is uploaded to Amazon from Omnivore, if the Amazon ASIN already exists and Omnivore has linked to the ASIN (via UPC or the ASIN matching feature) then an offer is added against the existing ASIN.  In this situation the information on the ASIN may not be changed.  

Omnivore will attempt to update the product details such as Description, Title and Images when the product data is uploaded to Amazon.  If Amazon fails the update then only the price and quantity is updated on the offer.

If the information on the Amazon listing is incorrect you can try updating the ASIN directly in Seller Central by clicking the 'Edit' button on your Manage Inventory page.  As these changes may also not update on the product it would be advised to test out a small update first before making a lot of changes.  

If the changes you make do not take effect you will need to request a product detail page change.  The instructions on how to do this on Amazon are below: