I had a similar recent experience trying to get a Trijicon SRO delivered to my home.I'm surprised that now, after the holidays, deliveries are still inconsistent.
I had a "2nd Day Air" delivery scheduled and confirmed for Friday, and didn't get an update saying otherwise. When it didn't arrive, I checked, and it had been rescheduled for the following Monday.
This was at work, so no big deal, but if I'd taken a day off to receive it I'd be pretty ticked.
Many people I know are now sick. Just a guess but I think things are going to slow down for awhile until staffing gets back to normal and consistent levels.
That's just a hunch and one I hope I'm wrong about.