I expected to run, and be freeeeeeeeeeee with my horse! But then, I realized I couldn't move. I seems like in an inclosed space, the horse couldn't move.

Steps to Reproduce:
1. So first, my horse was in a room about 20x5, with the height of 5. It was wearing iron armor, and a saddle of course.
2. Getting on, he couldn't move, he could pivot if I turned, and could jump, but that's it.
3. Putting him on a lead then taking him outside, fixes the problem, and you are free to move about, as long as you're on the horse the whole time with no interruptions. Meaning,inside, won't move. Putting him on the lead, then walking him outside and getting on him, the going back into that same space, he can move once more. But, if you do that, then get off and get back on inside that space, he won't move like before.