The first is fitting our harness like a regular harness. If all the straps are adjusted tight or snug up against your dog, this is not a good fit. A front leash connection requires the chest strap to be loose enough to give your dog shoulder room. When the chest strap slacks over your dog’s shoulder as you pull your leash, this is a good thing for your dog.
The second is fitting our harness too low. The back strap is either not adjusted at all or not adjusted enough. If the chest strap is close to the top of your dog’s front legs, the back strap needs to be adjusted more to keep him comfortable.