I'm fairly new at this and was having the same problem. Becky has some excellent posts to me about this if you scroll back. Neither one of mine seemed to care for the pasture and both were herdbound (or barn sour) to the horses in stalls. The gelding was the worse. The mare next to him and a stallion would scream at him when he was out. Keeping mine out of the barn working wonders.
I'll catch yall later. Off to aikido.