So I purchased the Fenix 6 pro, and really do like it. But I had this nagging feeling I may like the 6X better, so I ordered. I haven't decided which to keep yet but an odd thing has happened. My 6 says I'm at 149ft, my 6X says 62.3 ft. My actual based on google maps coordinates in the place I am standing is 135ft. I calibrated both watches and got the same results at 149ft and 62.3ft. My question is am I calibrating right? What is the difference between calibrating via GPS vs DEM? Should I really just be putting in the altitude manually, and it will stay correct from there? Do I need to calibrate compass first? Thanks, this is driving me crazy!!