gps issue on the rns 510 tiguan

hello, I have a problem with an rns 510 fitted to a tiguan..... it all works fine except that the detected position is not correct, to understand on the map the car is at a point, when in reality and in about 15-20 metres away from the point that indicates the map.... do you have any idea??

I have the same problem on an Audi a6 that I only the position is offset by 1666km
The car was in the Audi saying that the problem is gps antenna
Replaced
But the problem persists
At the moment I have not yet found a solution

test to see if audi have any update for this problem

still... no solution..... :-(