How to trigger Source Organization LOV when we default the radio button set?

Summary:

I'm looking for guidance on setting the default value for the source organization LOV based on user preferences when a specific radio button is selected, as per business rules.  
If no default is configured for the radio button group in the business rules, the LOV values populate from preferences upon selecting an option.  
Ideally it should default the value from the preferences, but it isn’t happening when we use the business rules to do it

Content (please ensure you mask any confidential information):

This is the Rule applied:

Below you can see, it has been defaulted but the 'Source Organization' which should have been defaulted from 'Preferences' does not populate.