[rtkwe]

Sometimes the consumer (more) directly pays when buying from overseas, most of the time you're right it gets rolled into the price at checkout if the company is large enough or just in larger prices buying in the US. I've had a few packages I had to pay extra import duties on with the UPS/FedEx agent fees tacked on top mostly kickstarters.

[xnx]

Understandable. With the intentional chaos since last year, tariffs were changing mid-shipment without any prior notice.

[rtkwe]

It's less that and more that the sender just didn't arrange to prepay it for the receiver rather than it being in flux. A lot of shippers do handle it to avoid the surprise for customers but some didn't have the setup to do the prepayment.