Repro steps:
Place 3 hoppers facing north
Place a hopper one block higher, facing north, but one block south of the other three
Place a chest boat on one of the lower hoppers
Hop in the boat and ride it so it is on top of all three hoppers
Sign out/In
Boat moves a little backwards
After reload, you can ride the boat forward again and if you log out again and log back in, it goes a little backwards again.
[media]Once the boat has gone backwards enough that can't unload items into the first hopper, it stops moving:
[media]Sample world file attached, you can ride the boat forward, log out/in and see the boat going a bit backwards from where it was left. It seems like a floating point or rounding issue.
I can reproduce the issue in the attached test world, but I can’t reproduce it from scratch. In the test world the boat is farther under the upper hopper than I can get a new boat to go. It seems that the movement on relog is triggered by the boat’s collision overlapping a part of the hopper’s collision.
I think it’s probably intended for entities to move when reloaded if their bounding box overlaps a block collision box.