It was most likely fixed in 1.16 because the floating vines happened in 1.14.
This does happen sometimes, but its (most likely) not because the player stays in the world. When you join a load, obviously it has to load the world, but when the world is loading, the player is already in the world, even though the loading screen is still show. This is most noticeable when you have an open world and a friend joins. At their spawning point, you can clearly see the player there, but no message has popped up saying the player has joined.
This glitch has not been fixed. I still experience this glitch in the latest verson of Minecraft Bedrock Realms and on normal worlds.
sure
I've tested it again, and it isn't an issue anymore.