We have a line of products for which we offer merchant fulfillment with five day handling time, with handling time set at the SKU level. Mostly this works fine, but we currently have one SKUs for which all recent orders have a ship by date the day after the order is placed. We can't currently fulfill this item that quickly, so all those shipments are being flagged as late. Obviously this is a problem both in that we don't want to disappoint or mislead our customers and that we don't want to hurt our account metrics with Amazon. Unfortunately, I've been unable to correct the handling time issue with this SKU.

When I go to manage inventory > edit, handling time is already set to 5 days.

I've contacted Seller Support a couple of times. One rep told me the edit button doesn't work for listings connected to a brand (Brand Registry connected listings, I assume) and that those listings must be updated via feed file, even if only one listing is being revised. I'm skeptical of that since I use the edit button to update listings for branded SKUs all the time, including setting handling time for other SKUs in this line. I sort of got the feeling the rep was just trying to get rid of me. I did try setting handling time via feed file for the listing in question, but as far as I can tell the problem persists.

Thanks in advance for any help!