Hi - We have had the same problem as other Linnworks users where Ebay use the first scan of the 2D code to determine when an item is dispatched. We spent months trying to get them to understand what was wrong with their system - pointing out that the dispatch date and delivery date / time were identical.
The way around this is to untick the box on the shipping configurations as explained in other topics.
The real solution is for Linnworks to add a prefix to the delivery code which the user can put in - so a delivery code 123456789 becomes AQ123456789. This will mean that ebay thinks the item is tracked; it cannot determine when the first scan was so no problems there; and the customer can see it is tracked and will not try to scam you. (We get several every week and have to find the 2D code to prove delivery).