When did you use and travel to the US? If you haven’t used US visa then IRCC may not process as CAN+. IRCC processed as CAN+ at their discretion.
Can+ visa is a program that is set by the government of Canada which is only for the visitor visa. This is a program of speeding up the process of the tourists who have visited Canada in the past 10 years or still holding a visa or having a US passport, these cases require less documentation.