I've owned 3 Edges so far and on each one, including my 2015 Titanium, the driver's seat was not exactly centered. It is annoying but I'm used to it now. I just figured there must be a reason for it and never bothered to ask about it. In a way I hope that the seat would not be adjustable from side to side. If it is then that would mean it could potentially loosen. Wouldn't want that. I guess it is what it is.
Please post if anyone finds a solution to this.