I think it is still a young dog. Is it possible one of the other dogs you are hunting with has got agressive with you dog several times on tree but when they hear you coming stop to keep from getting a additude adjsutment
if you like the dog find a good trainer and be hinest with them about what is going on with it see if they are willing to train it. i WOULD DEFFINATLY break the habbit of not listening if you call the dog to stop and come to you though. If you don't want to fool with it give it to someone for a house pet or something please dont be like a lot of sorry People and sell it as it will just ruin the dogs life and possibly a new person into the sport. Just my 2 cents