I've had similar stickers stuck to (tracked) parcels from China. The China Post tracking never shows in the AP tracking until after it's been delivered (a day or 2 after). I don't know if the AP sticker shows up in tracking as I've never needed to check it because I've already got the parcel!

I've also had them attached to the untracked parcel post parcels (with the red and while parcel post sticker). Again, I've never checked the tracking number or scanned the bar code because I've not needed to.

Looking at the OP's last photo, it's easy to see why sellers would be concerned about delivery. I put both numbers into my My Post app. The first tracking number shows as awaiting collection from St Marys PO and then later in the day a customer enquiry has been lodged. Then I'm guessing a sticker has been attached and that number entered into the system as it was generated from St Marys. The seller wouldn't have that tracking number, so even though it's showing as delivered to the OP, it's not to the seller.

Parcel lockers, another way for scam buyers to claim INR. Looking at the OP's tracking, it would be easy to do.