Summary:
Player will sometimes automatically crouch (sneaking) when climbing (3+blocks) ladders, vines, twisting vines, weeping vines under any full block.

Steps to reproduce:

1. Place 3+ blocks (ladders, vines, twisting vines or weeping vines).
2. Place any full block on top of them.
3. Climb the placed blocks.

Observed results:
The player will automatically crouch when they hit a block.

Expected results:
The player should not automatically crouch when they hit a block.

Video:
MCPE-166569.mp4