Chests don't merge together if there is merged chests nearby

Chests can now be placed next each other, without putting a space between them. But now, chests don't create double chests if there is already double chests near them.

How to reproduce:

1. Open a world
2. Place chests on the ground: they will merge two by two
3. Put chests on these chests: they will not merge

What should arrive:
Chests should merge together, like before, two by two.