It usually starts when on a hill/mountain, but it has happened in all biomes. (Has happened on or off a horse) It won't let me auto jump up one block like normal. I have to hit the jump button. Then it seems like I cannot walk or run into a chunk? Sometimes I can go down a ways and it will let me go in that direction once I am past it but then you can't enter that chunk from a different direction. All animals in the chunk freeze up and if I get off my horse and the horse tries to walk into it it will get stuck and start shaking. If I try to sign out and then get into the world again it will drop me from the sky over the world spawn point then respawn me in a bed. It does this when walking and when riding a horse. The horse will stay at the place where you were when you left the game and you have to go find it again.
Thank you for your report!
However, this issue has been closed as a Duplicate of MCPE-38868.
Please add a vote and any new information to the main ticket, which will be updated accordingly.
If you have not, you might like to make use of the search feature before making a new ticket, as it's likely that the issue has been reported already.
Quick Links:
📓 Issue Guidelines – 💬 Mojang Support – 📧 Suggestions – 📖 Minecraft Wiki