My GSD is 11 months old. Intact male. I've had him since he was 9 weeks. Everything has been great. We take daily walks both on-leash and off. My training tools are a prong collar for leash walking and a E-Collar for off-leash. I have a solid recall command for him. The only problem, and I use the word problem reluctantly, is when he meets other dogs. He comes in submissive like he should and allows the other dogs to smell him without any fuss. But when he goes to sniff for himself and a dog won't allow him to he won't get the message. Is this just an age thing or should I be correcting him if he goes back to sniff a dog who has already warned him?