My horse was exactly the same as the horse I bought for the first couple of days before completley losing it. For about three months she was constantly rearing/bolting/bucking/etc and we couldn't work out why. Eventually we realised that she was from an area where the feed had super low sugar and so when exposed to our super lush grass she became a menace. Now we monitor her feed 24/7 and if we do let her on the grass it's only for a few hours after dark (the sugar levels are apparently lower then)
Yes my horse started having these horrible behaviors like rearing up and being down right ugly at one barn. As soon as I moved him to another stable he was back to the horse I originally fell in love with. Listen to your horse. He is trying to tell you something the best way he knows how.
Changed how? Horses will change with routine and surrounding changes. Moving from one place to another will change the smells, sounds, and routine. If he is more aggressive, you will need to work on setting extremely clear boundaries. If he is more fearful, then exposure is your best route.
in my opinion the behavior of the horse changes when you change stable or when it is new but the only thing that you can manage to do right now is to help your horse feel more comfortable and change its behavior and to wait because it always needs time for the horse to get used to a new place .What my suggestion is is to give your horse time and also practice more and more so that it can be better and better
You need to make a list and see what the differences are. Maybe he need a companion, companionship is huge to a herd animal!
Based on what I know of other horses and my own experiences with my horse, although they often seem to prefer some places to others, the strong neagive reaction is not that common. If I were you, I'd change of stable, with a bit of luck, it won't happen anywhere else :)