I have attached two clips that illustrate the problem quite well. I believe people refer to it as jump lag. In the first video with a player standing on a block, moved by a piston: On one person's screen a player falls and sort of lags and teleports back up while on their pov they're not moving. In the second video I, the player, am running and jumping over lava. From my pov I did not fall in the lava, i succeeded on every jump yet randomly caught on fire. From another persons perspective it looked like i fell in and somehow immediately bounced out. It looks like hosted worlds failing to detect players' positions and then correcting them. It seems, yet i don't say this with 100% certainty, that it only occurs in multiplayer worlds. In any case it didn't seem to occur when i turned multiplayer off. I jumped over the lava and I wasn't set on fire mid air. To clarify, it happens to the host of the multiplayer world as well as people that have joined it. I believe this might have something to do with MCPE-60856 as I had that glitch in a similar context. In MCPE-60856 when i player opens and jumps on a shulker box others freeze. I have a shulker box parkour where that happened, the parkour being the place where i first noticed the jump lag.