Strange eBay order arrived from Amazon

I ordered an item with free shipping within the last couple of weeks. It arrived very quickly, but was in Amazon shipping box with a PRIME shipping label. I went to post feedback, and noticed eBay did not show the package as delivered yet. It stays that way for several days and when it does notify me of delivery, none of the tracking matches the actual delivery. The dates for it to be at another facility out of state were the dates it was actually delivered, delivery date was several days after it came as well in the system. At first I thought maybe I was going to receive two of them, but the delivery marked today left no package today (no photo in the tracking either). All the updates are from UPS, but it was delivered in a blue Amazon truck.

My order was correct. But the entire thing is just strange. Their tracking showed updates on weekend days when the package was already delivered. Are people allowed to sell on eBay and drop ship from Amazon instead? Also wth is up with the tracking? Anyone else have any strange orders like this one?