Packaged marked as delivered at mailbox but it was not there

I got a notification and waited about 10 minutes for the usps delivery driver to finish up and leave. When I opened my mailbox there was nothing there.

I called USPS and they said that sometimes they get marked earlier as delivered but that employee might just delivered to the door.

It's been two hours.

I asked my neighbors if they got a package and the lady was really nice and went to get her mail and when she return she said there was nothing in her mailbox.

Do I just contact the seller now? How long do I wait? There's 88 apartments where I live. I can't be expected to ask every single one.