Have the same problem. I think ebay are delaying the upload so those who only get paid when it shows delivered have to wait longer. The longer ebay and their payment processor hold on the $$ the more they make. Of course, like the original thread, we will never know why as ebay are dodgy.
The trick is to use AP tracking data, if you feel a need.
My AP MyBusiness page gives me tracking statuses without having to plug in tracking numbers, so if I cared I could find the status of my last 100 parcels in one click.
