When the Sage Connect company is created from Sage 50 CA, it defaults to English[US], probably from the browser settings where it's always set to English[US] for most Canadian users.
When it's on the English[CA], the US transactions get the US$ currency symbol and the Cdn transactions just get the $ sign, which is preferred. If the company is created from Sage 50 CA (English), it should default to English[CA] so the currency symbols better match Sage 50.