GPS Quesiton/Lost signal in DC

Not sure if you guys ever experienced this but I have one of the high end Garmin GPS units which is great because of the job I have. I don't use a smart phone for navigation. Two days ago it couldn't reroute in Washington DC.  I was dropping my daughter off to college and the GPS couldn't recalculate to get us back to 4th street. This thing is 98% accurate and I always keep up with the maps.  Is it because of the way the streets are arranged. DC and MD are a fuckin mess as it is.

81 FBI agents are watching your every move, act accordingly.

Ha ha probably...