Be very careful with entering Canada Post tracking numbers on Etsy for shipments within Canada. My shipping on time with tracking has always been at 100%, I haven't shipped without tracking in probably 10 years now. In the last two months I have had three orders when entering Canada Post tracking numbers on Etsy default automatically to FedEx. I have never ever used Fedex in the 15 years that I have been selling on Etsy and I have chosen the Canada Post option every single time that this has happened and the numbers I entered were correct. So now it has dinged my Star Seller Stats because of an Etsy glitch.
Me too, I'm in Canada and only ship via Canada Post. Some time ago I went to insert a tracking number and noted that Etsy had defaulted the 'shipper' information to FedEx. Fortunately I noticed before hitting the submit button. Ever since then I have checked to see that only Canada Post shows up in the 'shipper' box.