GPS Settings affecting Quickdraw Contours accuracy

Wondering if anyone else has had this issue, We created QD contour maps with a Stryker unit on a remote lake over the last few years and are the only people to have mapped it for . We bought a Echomap unit and downloaded the Active Captain maps and found the two units had a large (up to 80metres) in the GPS location between units on the existing maps and waypoints

The Echomap unit had been set to System/Satellite Positioning/ WAAS/EGNOS ON and GPS and Galileo 

The Striker had GPS only. When we changed the Echomap to be GPS only the positions were more similar. We used the Echomap to create QD maps but they did not line up at all with the old maps using GPS only. Will this screw up all the Community maps ? Is this a problem for Community maps submitted using different GPS settings..