If you have a multi-step form with a condition on a field value, and if you select a particular value, go next and then go back and select a different value, then the form state seems to keep the page you visited when you selected the initial value.

This means that changing a value of a field with condition on it after going back keeps pages you visited before modification (which are not on the new branch you follow after changing value).

So there should be a way to remove the steps from form steps for steps which will not be visited based on changed criteria.