Items sent in FBA shipments are being deleted from the Inventory

Hi,

Is any one else having this problem? Active inventory items that I am sending through FBA shipments are for some reason getting deleted from our Inventory before they arrive at Amazon. I can't work out ( and neither can Amazon help desk it seems) why the items are being deleted. I can add them again through the add product page using the same SKU but still all the items are being deleted somewhere along the shipment process. It is bewildering. They do not show up on the Manage inventory page and show as deleted in the FBA Inventory page. When they are processed through the FBA depot they end up in Stranded Inventory until i add them again.

Any thoughts on why this might be happening. I have sending FBA shipments for 15 years and not had this problem before