Has happened to me recently and this was for a local purchase.. Single order.. 3 pcs of the same item from the same shop. Order got split, box one delivered next day or so and the other 2 boxes, days after.. I'm guessing it was a logistics or stocking issue.
Product being used on? Luckily, I no wait and just ordered earlier.

Opps.. Sleepy brain.. It's probably cuz they haven't activated it yet.. Now can use d..