Horses are smart. Sometimes their behavior differs based on how they’re being ridden by different riders (or with different tack stet-ups) and sometimes it differs based on who they think they need to take better care of.
My former mare was a typical chestnut TB who had strong opinion on how she should be ridden. She had a huge stride, would do the leave-outs given the chance, and if you even thought about looking down or leaning up her neck she would dodge right at the last second every time. It took me forever to figure her out and even 10+ years into our relationship had many a disagreement. Everyone who rode her, regardless of ability, had Holly stories about doing a 3 in a 5 stride or winding ass-up in a jump. However there was a tweenaged boy who lessoned on her for a while that she LOVED. She would crawl along with him over the bittiest of jumps, add strides, and never offer to stop. We always joked that she loved him because he was up there thinking about what he was going to eat for dinner that night instead of worrying about strides and distances. It was really adorable and also a little infuriating