Sending route to zumo 595. The route changed , don't know why

Hi All, I don't know what happened, but I plotted a route in BaseCamp and sent it to my Zumo 595.  This was a local test route I plotted so I could learn how everything works before going on a trip, and boy am I glad I did.   The route got changed in the Zumo and had me going in circles.   What did I do wrong?  And how do I avoid this?

Thank you very much

Mary