Closely relates to MC-163196, which concerns blocks which cannot be placed on the side of honey blocks. 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 top of slime blocks, but not on top of honey blocks:

• Glow Lichen
• Sculk Vein
• Torch, Redstone Torch, Soul Torch
• Buttons, all types
• Lever
• Bell
• Coral Fans, all types
• Twisting Vines
• Sea Pickle
• Scaffolding (MC-165404)
• Redstone Wire
• Redstone Repeater
• Redstone Comparator
• Pressure Plates, all types
• Doors, all types
• Rail, Powered Rail, Detector Rail, Activator Rail (MC-163248)
• Lantern, Soul Lantern
• Coral, all types
• Amethyst Cluster/Buds, all types

Expected results

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

Actual results

None of the above listed blocks can be placed on top of honey blocks. Only a small selection of support-needing blocks (i.e. all signs, all carpets, all banners, cake) can actually be placed atop honey blocks. This is, again, despite the fact that honey blocks have been officially stated to be the stickier of the two.