on Nintex Forms for Office 365, new responsive designer.
After my users submit a new form, whenever another user opens the form to view the details, the controls change. For instance, the form automatically calculates the Department by setting the Default value to userProfileLookup(pContext].]Current user login name],"Department"), and the user selects and employee in a List Lookup control whose available selection options are determined by the user's Department. When another user opens the form, it re-calculates the Department and clears away the selected employee.
Yes, I have already added rules that mark the control as Read-only when in Edit mode and Display Mode rather than New mode. That did not prevent it from changing the values.
(oops, I forgot the word "not" in that previous sentence ... I added it now)