7.1" HDD Nav Freezes at the same intersection

I have a 2012 Five with the 7.1" HDD Premium Nav with Entune. I have noticed on two occasions, when making a left turn at the same intersection, the Nav froze at the 45 degree turn angle. 200- 300 feet later it was back to normal.

This is an underpass with a highway bridge over. I suppose I could be losing the GPS signal there causing it to freeze. However, I have been under much bigger bridges, sometimes multiple levels, with no problem with the nav. And I thought these built in units are supposed to have dead reckoning, and should work in even tunnels.

I am using the split screen feature, the left side is the map and the right side is the energy monitor. Only the nav side froze and the energy monitor side was updating.

Is there such thing as a GPS jammer that could be messing with my signal at that location? The unit itself is not displaying any error. This is the only place and the only problem I with this nav.