Rendering condition parameter 'If hidden, Model field changes should be...' set to 'Cancelled' doesn

We have a number of fields set to conditionally render on a ‘Create’ page.  On each of them, we have set the rendering condition parameter ‘If hidden, Model field changes should be…’ to ‘Cancelled’ (not ‘Retain in Model’).  When we eventually save (we move through a series of screens using a [next] button) until the final page where we present a [SAVE] button ), both fields that were conditionally rendered with mutually exclusive conditions now contain data.  Example.  Background - Field Employee Name is conditionally rendered when Hire Type field = Existing Employee.  Field First name (and other fields) are conditionally rendered when Hire Type field = New Hire.  Both fields’ rendering condition parameter ‘If hidden, Model field changes should be…’ are set to ‘Cancelled’ (not ‘Retain in Model’).   User Action - The User first selects Hire Type = Existing Employee.  The employee name field is displayed.  The User selects an employee name (this is a look-up field).  Before proceeding to the next screen or saving, the User changes his mind and changes the Hire Type field to New Hire.  The employee name field is hidden, and the First Name field (and other fields) are displayed instead.  The User enters a value in the First Name field.  The User clicks on the Next button to move on to the next screen (no save yet).  At the end of the screen series, the User clicks on the [Save].  The record created has a value in the Employee Name field AND the First Name field.