Some blocks can be stacked vertically while jumping with a sneaking.
(It's difficult to convey in text, so I'll post a video as well.)
(Fast-forwarding or changing file format due to capacity.)
For example, Full blocks, Half blocks, Stairs, Fence, Grass Pane, Iron Bars, Chorus Plant...
But there are blocks that can't do that.
For example, Anvil, Cobweb, Banners, Walls, Fence Gates Trap Doors, Carpets, Top Snows, Daylight Sensor, Chest, Brewing Stand, Lectern, Enchantment Table, Grindstone, End Portal, Hopper, Chain.
Linked issues
Attachments
Comments
[Mod] OcelotOnesie
daidainaso
Thank you for your report!
We're tracking this issue in MCPE-51825, 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