I am not aware of the issue as described above. By default, the proper behavior is that Cancel button from qListForm should always redirect it to the source web part page.
When you are taken to the qListForm page from qListView, either by using Create/View/Edit menu, you can check the URL address bar and notice there is query string Source. The value to this parameter is where we would consider going when Cancel button is clicked, depending on the propery "Cancel Button Click Action" settings you select, such as "GoToSource" or "TrySourceThenGoBackUrl".
Could it be that the "Go Back Url" property is set in your previous scenario that points to allitem page?