Summary:
Some blocks cannot be placed on the underside of the sculk sensor. List:

• Button
• Lever
• Weeping Vines (MCPE-104717)
• Roots
• Pointed Dripstone
• Amethyst
• Glow Lichen
• Sculk Vein
• Cave Vines
• Lantern
• Soul Lantern
• Bell
• Spore Blossom

Steps to reproduce:

1. Place the sculk sensor.
2. Try placing the above blocks on the underside of the sculk sensor.

Observed results:
These blocks cannot be placed on the underside of the sculk sensor.

Expected results:
These blocks will be placed on the underside of the sculk sensor.