Note:
Boats rise and fall slightly when in water constantly.
The bug
When boats rise, entities that would normally stay on boats attempt to fall through. Entities like armor stands (or others that don't mount boats) fall straight through whereas players fall through server-side, not client-side. This will make suffocation bubbles appear and disappear 3-4 times as the boat rises, but never as the boat falls.
Video Example
Related issues
is duplicated by
Comments
migrated
Makzevu
It appears that it came out about a block below, but alternatively I could just spawn a pig, have them look at me, and see them nod in my direction. That's actually the main way that I discovered that it was a thing. A few days ago, I also asked my friend if I was "teleporting up and down" while on a boat, and they said yes.
migrated
I've confirmed this bug is present on Android.
Another Question: How did this friend join the world? And who was hosting? Over LAN, Servers, or Realms?
Next test:Try to make a contraption based of this bug that would prevent you from teleporting back up to the boat. move a few chunks away, then set the time to night. See where mobs spawn: they'll spawn either in a ring around your clientside location or around the boat (radius approx. 24 blocks)
Makzevu
I was on my friend's Xbox world, connected through Xbox Live, not a LAN, server, or Realms.
migrated
Okay, we're getting somewhere!
Create the device mentioned in my last comment on your friends world. He/she may need to help you determine if the contraption works. Once it does, have your friend enter the end (so he/she doesn't spawn any mobs and mess with the results). then perform the procedure described in my last comment.remember, mobs will spawn approximately 24 blocks away from the player's serverside location( where your friend/the server sees you). If desynchronization is achieved, your clientside instance (where you/your device thinks you are) will be able to enter that mob-spawning area and not affect the spawn rates in any way.
Also, I recommend checking out Docm77's older video on Client-server desynchronization with boats, so you can see what I'm testing for. He demonstrates the Mob spawning phenomenon I've attempted to describe in a very understandable manner.
PS: when you do this, please tell me how to make the contraption, so I can attempt the procedure myself.
Makzevu
Relates to MCPE-65094.
Edit: That's also the reason why the contraption is impossible.
Makzevu
I think it's entirely necessary to, at least, refer to shulkers in this report because a lot of information listed here for boats also apply to them. Items appear one block below the player's eyes when tossed from the inventory, and mobs that are looking at the player nod up and down (similar to when boats float up) when the shulker opens upwards. However, mobs do not fall through their bounding box, only players do.
On an unrelated note, items, shulkers, and boats ignore each other's bounding boxes completely, meaning that the player can drive a boat straight through a shulker, and that items can fall straight through boats and shulkers.
[Mod] LateLag
Seems to be fixed in the latest beta, can anyone else confirm?
[Mod] LateLag
Nevermind, still an issue. It's just less noticeable due to MCPE-95941.
Picomos plays
Multiple device and affect 1.20.10.20
Are you sure it desyncs the client and server like you said? Try bringing another player account into the world, and have them tell you where you end up while attempting the replication of the glitch. Alternatively, attempt to toss an item from your hotbar. if it doesn't come form your position, the client and server are desynced. I look forward to hearing the results.