Quite a lot of services don't update.
Some Royal Mail services only show when the item is dropped off and then again when it is delivered.
When you paid, Ebay sent you an email with a short range of estimated delivery dates.
If your item doesn't arrive by the latest estimated delivery date, you can open an 'item not received' claim.
"There are two ways to be fooled. One is to believe what isn't true; the other is to refuse to believe what is true.”
Søren Kierkegaard, Danish philosopher (1813 - 1855)