All the teeboxes i use on GRINT are wrong for the courses. Anyone else find that issue? Played the back tees and found on GPS it located at the front.
A lot of times Grint just isn't updated. But, from working with their staff a lot over the last few years, their Customer service and IT people are awesome! Email them the course and a link to the USGA course rating/slope and they will update it within the hour typically.
haha and I didn't read all of your post.... I thought you meant the ratings and what not were off for different tee boxes....
in your case, I would think that would be due to GPS service/coverage.