Closely relates to MC-163196, which concerns blocks which cannot be placed on the side of honey blocks, like how MC-251040 concerns the top. Also relates to MC-163077.

The bug

Slime blocks and honey blocks are both full 16x16 cubes. However, despite honey officially being said to be the "stickier" of the two, there are a large number of blocks which can be placed on the bottom of slime blocks, but not on the bottom of honey blocks:

• Vines
• Glow Lichen
• Sculk Vein
• Buttons, all types
• Lever
• Weeping Vines
• Cave Vines (MC-221506)
• Hanging Roots
• Amethyst Cluster/Buds, all types

Expected results

Since all of these blocks can be placed on the bottom of slime blocks, they would also be able to be placed on the bottom of honey blocks.

Actual results

None of the above listed blocks can be placed on the bottom of honey blocks. Only a small selection of support-needing blocks (i.e. lanterns/soul lanterns, bells, spore blossoms) can actually be placed below honey blocks. This is, again, despite the fact that honey blocks have been officially stated to be the stickier of the two.