Roger has become very buddy sour.

He will bolt when he is with his friends, but once they are gone he will simply stop and there is no persauding him. He will wait until a friend comes and then bolt again. I have ridden him by himself and that day we accomplished so much. I feel like this is becoming a big problem as he is so excited and distracted by other horses! We can simply not get anything done and it's
dangerous! We caused Romeo (who is very young.) to bolt with his rider because he wanted to race Roger, and the girl was very scared. Also having no choice tried to pass Buster and he tried to buck Alexa off as a result. (we were suppoused to cut across the middle, there were jumps there hence not a lot of room to pass!) I'd really love to stop causing everyone so much trouble

With us jumping now I also really would like to feel like I have control of him. Help?