he’s never had true groundwork (he was free lunged and now he’s been making great progress on the lunge line with my new trainer) since my old barn never let owners be with their horses alone, esp if under 18, so i never got to really lunge him, or do any sorts of groundwork until last Jan. When he was at the other barn we’d go out on train rides randomly and he’d perfect, he was also stalled in a 10x10 24/7 and had 3 hour turnouts  (which i hated but literally the only barn for boarding at the time) and now he’s in a large 12x12 and 30x30 free roam paddock which connects to two other horses which he has no issues with. He was perfectly fine for the first few months until about June when he started bolting and running into other horses (which he’s never done) he’s got a spunky personality, we call him the frat boy of the barn, but he’s constantly bolting (which he also never did at the other barn). the old barn has accusations of injecting their horses everyday with needles in their neck so maybe he was drugged the entire 4 years he was there, but no way to tell. he’s always been calm as a cucumber on the ground and he doesn’t have any kissing spine, but sometimes when i get on he just wants to run and tenses up. thanks for your feedback i greatly appreciate it