Tractor position icon does not adjust when you zero against a benchmark.

Symptoms : 
 You are parked over a physical benchmark and want to adjust the map location so that the related on-screen benchmark icon matches the location on the tractor icon. However when you perform the “Zero using a marker” action nothing changes. The icons for the benchmark and the tractor remain separated. 
 
 
 Cause : 
 You have forgotten to check the “Zero X and Y (lat/lng) offsets” box. 
 
 Solution : 
 Check the “Zero X and Y (lat/lng) offsets” box before pressing the Ok button.