I may be way off, but is it possible your plate is installed backwards? I had one of these years ago and I'm pretty sure mine had the slots on engine side. That made it easy to change engine mount by only loosening the bottom bolts and removing top ones to remount. Also, that would mean the larger face of jackplate would better spread the weight/pressure over the transom. However, if I'm wrong, it also looks like the trim at top of your transom is preventing the inner plate from fitting solidly to transom...