Auto Jump will trigger sometimes trigger when it is not needed - particularly when going up stair blocks.
A secondary effect of this is that this is why going up the stairs takes so much food with autojump enabled. - The autojumping occurs with or without the jump boost, you just don't see the effect aside from hunger most of the time.
To duplicate: somehow get the Jump Boost effect (potion or beacon comes to mind), make some stairs using stair blocks (at leat 5 blocks high). Make sure auto jump is it to on. Walk up (dont' sprint) the stairs. Repeat without auto jump setting enabled. The differences should be obvious.
Thank you for your report!
We're tracking this issue in MCPE-64793, so this ticket is being resolved and linked as a duplicate.
If you would like to add a vote and any extra information to the main ticket it would be appreciated.
If you haven't already, you might like to make use of the search feature to see if the issue has already been mentioned.
Quick Links:
📓 Bug Tracker Guidelines – 💬 Community Support – 📧 Mojang Support
📓 Project Summary – ✍️ Feedback and Suggestions – 📖 Game Wiki
-- I am a bot. This action was performed automatically! The ticket was resolved by one of our moderators, and I left this message to give more information to you.