I added a picture of what it looked like
The thing is, the other one is about the leads becoming invisible, and it says in the description " they still acted like there was a leash but the visual leash was gone" in mine, the leash broke, and was on the ground as an item, and the horses were able to wander away. This was on a Singleplayer world, so it was not other players. I don't mean to be a nuisance, but this is annoying when Dinnerbone is always tweeting about how we should report bugs, and then I report a bug, and it gets incorrectly counted as a duplicate.
Pretty sure I searched for "Horses detaching from leads"
I actually just saw a video saying that this was supposed to happen, and I have no idea how to delete this, so...