But, Dreamerr is correct: There were supposed to be multiple shipments. If one box gets stopped, that's random. If multiple boxes get stopped (TO BE CLEAR: I don't know that this happened), then usually it is stopped for merit.
eg, I've seen footage of Customs taking a steamroller to counterfeit merchandise. (China being a pretty good source of that.)
Maybe US Customs thinks the Ascents are knock-off DaVinci's and all of our orders are going to get crushed under a steam roller!
[For those playing along at home: THAT IS A JOKE. I don't think that is really why they are stopped, but an example of one reason. Paka doesn't need the real thread flooded with 200 messages saying "Nigel said our units are being crushed by the government!!1!!"]