Maybe this is what happened to my order . . .

From my experience, sending packets from Europe to the USA via DHL used to take 3~4 days these past months, and it almost doubled for a couple of weeks.

This apparently simply is due to the snowy weather.

I've had some terrible experience with DHL though : one of the first packets I sent arrived open and empty. After a lot of phone calls and emails, the contents arrived back at me a month later with no further explanations. All the products boxes were smashed open, yet everything was complete. More and more these companies rely on sub-contractors, so it's pretty difficult sometimes to find out where bad things happen.

When you read their conditions regarding insurances, there will always be an exception, like basically they do not guarantee the packet to have the same weight at arrival...! Actually packets are only weighed once, at pickup. If these were to be automatically weighed at each major change, while the tracking numbers are scanned, it would prevent empty packets to be delivered.

So, I can only suggest to pick up the phone and try to talk to a human (which can be a challenge sometimes). There are times a packet can simply get forgotten/lost in a corner of their facilities for whatever reason. It once happened to me a couple of years ago, with a packet arrived at the final distribution facility, to then being "lost".

Even though it's been a while, if their track & trace system let you know where it's supposed to be, going on site can also help, as the people you would get on the phone in a remote place will not always be of great help. You shouldn't wait this long though, as it usually make things difficult to find back, and some couriers do scrap their "abandoned" packets once a year.