2011 Yukon gps voice not working

[Amaster]

Okay so I have a 2011 Yukon slt that has the factory touch screen headunit in it, and when I try using the GPS the only thing that I can get it to say is please proceed to the highlighted route then the guidance will start, any ideas why I don't have more guidance? P.s. wasn't a gps truck when I got it.
Thanks Flash!