Basecamp created route on 2798LMT not following route

I created my latest route on BaseCamp, including several via's to force the route to roads I desired. I then downloaded it to my 2797, where it showed the exact route created in BaseCamp. However, when following the route on my GPS, it took me onto different roads than was shown on the map. On BaseCamp I have the option when downloaded. to follow it exactly. What gives??