VERY inadequate grilling instructions.  Your instruction booklet is full of "don't do's" and practically nothing about "how to's".
Example: How long at what temp setting should you cook a 1/2" hamburger to medium, or well, or medium rare.  You constantly empathize keeping grill lid shut and judt flip once so how is a person supposed to know when the way you want it.  I've cooked hamburgers twice now and first time under cooked and second over cooked.
Did a NY strip steak and it came out beautifully.  But I did lift lid multiple times to check it.