I had similar behaviour from a previous VW
Turned out the coax had been crushed, causing a signal loss from the antenna. The map still receives inputs from the wheels and steering angle etc to update the map (useful in a tunnel for example) but there is no accuracy reset to confirm exact position from the GPS.
I'm not full bottle on the 2016 nav functions - is there a way of displaying # of satellites it is using?
Have you changed anything in the car? Possibly a connection has come loose - I think there is one in the boot headlining between the GPS unit in the roof and the rest of the car. 
For your question, is there a number on the middle connection in the diagram? This is distance in mm, and could give a clue on it's location?
				
			 
			
		 
			
				
			
			
				2010 TDV6 3.0L Discovery 4 SE remapped to RRS output, Alaska White, GME XRS-330c, IIDTool BT, Dual Battery, Apple CarPlay, OEM Retrofitted: Cornering lights, Door card lights, Power + Heated Seats, Logic 7 audio
			
			
		 
	
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