Autojump triggers even if Steve can't jump on a block

What I expected to happen was...:
When I came to the "wall" that looks like the one on a screenshot Steve don't need to jump

What actually happened was...:
Nevertheless there's no possibility for Steve to jump on a block, autojump triggers

Steps to Reproduce:
1. Сome close to the blocks setup like on a screenshot with autojump enabled
2. Press "W"