The thing with border crossings, US or Canada, you just never know. Fastest ever was a Canadian crossing. Wheels stopped for less than a minute. Us crossings have not been much more. Longest stop was almost an hour. Canadian again. Longest US not much less. So much depends on the officer you come into contact with. Maybe the vehicle before you was a PIA. Now the officer is not in good mood for you. Human nature I guess. Go with the flow.
Worst enforcement officer of any type was a young female Colorado SP ranger. Her behaviour has taken Colorado right off our future visit list.