Maybe this will work:
Set an on change event on one radio button → On Change – Call a Nanoflow → In the nanoflow check if the enum value of that radio button is empty → if it’s not empty (when a value is selected) change the other enum value of the other radiobutton object to empty→ if it is empty just end the nanoflow.
Do this for the other radio button aswell.
I hope this works.
In Mendix, when you use the radio button widget for selecting in an enumeration for example, the selection automatically changes when another option is selected. Perhaps you mean checkboxes?
Tim van Leeuwen