Say that a solution to a Sokoban puzzle with only 2 boxes is box-isolating if and only if there are step numbers $m$ and $n$ such that for one of the boxes:
- All of its pushes were between step $m$ and step $n$, and:
- The other box was not pushed between step $m$ and step $n$
Is there a Sokoban puzzle with only 2 boxes such that there is a solution but there is no box-isolating solution?
I do not know the answer to this question.
It is related to this question I asked on cs.stackexchange.