Wrong currency showing in cart and checkout

We just started noticing the issue on the website last week, but after running a report it looks like it has been happening periodically for a couple of months. Our default currency is USD. When a Canadian customer comes to the website it shows the Retail price in CAD, but the wholesale price is showing as USD. When they go to the checkout it just shows USD, but when it charges them it deducts the exchange off of the USD price, so we are losing 40% on all Canadian orders right now. We did the new update and the problem is still there.