Unfortunately, it doesn’t help if the issue is the package has yet to be handed off to the shipper, which I believe is what’s happening here. On another note, 3 out of my last 4 Amazon Prime deliveries have been late (and tracking info wasn’t always accurate there either), so it seems as if the whole fulfillment and logistics chain is struggling to some degree under the weight of the season.
Edited to Add:
I have no doubt Republic is doing everything possible to alleviate the situation. I believe the reality is the “supply chain” generally is strained.