Quote Originally Posted by motoguy128 View Post
Any chance it was installed backwards so the drain holes in the track are inside rather than outside. Maybe they ordered a LH instead of a RH and the installer tried to "fix it" by installing it backwards.
This seems most likely here. You can determine the inside from the outside by looking for "weep holes" which allow water in the track to escape outside- they will only be on the outside, not the inside, and must be kept clear of debris to work properly.

I also have a problem with the response you got from Andersen. They make a very good product and while sliders do tend to not seal as well as French Doors that swing, a properly installed Andersen shouldn't have any noticeable air or water leakage for many many years. Something is very wrong here and it's most likely to be with the installation, not the doors.