The issue has happened a couple of times. Sometimes when dismounting my horse the horse disappears. The first time it came back and appeared out of nowhere. Nothing hostile was around me at that time. This last time it completely despawned and did not come back. I had diamond armor on the horse and it had 1 whole heart of damage when I dismounted. I intended to fight hostile mobs that were beginning to surround me in a town at night and the horse just disappeared. As an update I did find my horse again but it is a bit strange to dismount and have it seemingly disappear completely for several minutes.

What I expected to happen was...:
  The horse to appear beside me and stay put

What actually happened was...:
The horse with it's saddle and diamond armor completely despawned

Steps to Reproduce:
not sure if it is a consistent bug or not but it seems to happen only when dismounting a horse