Most horses are backed in round pens. Maybe your horse has had a bad experience? You could try and let your horse in on his own and leave him to it for 5/10 minutes then go in and walk round? I would say just try things to gain his confidence back😊
Maybe just work with your horse at the work and trot until you're comfortable and going well, then work on the canter?
Lungeing and round pens 😫 He gets worked up and can start to get full of himself
my horse just bucks consistently in the round pen when I lunge him at the canter.
My horse hates going in round pens because he has associates bad memories from his previous owner. What kind of issue is it?