[Ashley V]

I know you said he has a ton of toys, but he also could be getting bored. Maybe instead of letting him have the same toys all the time, try splitting them up in groups. Give him one group of toys for like a week, then switch it up. It keeps them entertained and they think that they are constantly getting new toys. Also, maybe when you leave, give him a kong with some peanut butter or treats inside to keep him busy. I do this with my two sometimes and it keeps them quiet.