Bug with scaffolding

When you put a lot of scaffoldings together and the you remove the bottom one some scaffoldings remain in mid air with no contact with the ground.

What I expected to happen was...:

I expected that all scaffoldings will get removed

What actually happened was...:

After all other scaffoldings were removed, 3 remained in mid air

Steps to Reproduce:
1. Put a lot of scaffoldings together and with only 1 touching the ground (a lot = a few stacks)
2. Remove the bottom one
3. Some will remain in mid air and you can use other scaffoldings on them but they will disappear and only the new scaffolding will stay there