I have a 24 y/o Tennessee Walking Horse. Since we were both 11, I used a light grazing bit. Last year we briefly switched to a snaffle when my tack was stolen and I was borrowing. He is still very spunky and will RUN back to the barn if allowed, so generally we just walk or do an easy running walk. I make him stop or turn in a circle if he acts up.
We just relocated to a new state in February and I decided to try a Hackamore bit on him since he is older and I thought it would be easier on his mouth. The instructors at the barn looked at it and says it seems to be fitting correctly. However, when we turn in the direction of home he becomes very agitated when I cue him to slow down, he begins dancing around, throwing his head up and lifting off the ground on either his fore or rear hooves. He has NEVER done this before so it is a little startling and I have had to walk him home 2 times for safety just because we have to return along a road.
He was my first and only horse and we were always on the same bit so I'm not familiar with all the different types. I know the general idea with the most popular types, but I was trying to see if anyone has any insight into my problem or helpful tips. I try to use the lightest pressure possible, but is perhaps the nose pressure bothering him?