Mapping issue for choice field in Form layout

Hi All,

In my custom application, there is one field called "include_custom_data" (choices - Yes, No, None) created in a table like "custom_requested_item_aux".  
And there is another table called "custom_requested_item". Both tables have reference to each other.

I have added the "include_custom_data" field in the form layout of "custom_requested_item" table in one section using dot-walking through "req_item_aux" field. 

I am mapping these field value using record producer variable called "include_custom_data_var". ( choices - Yes, No, None). For both dictionary entry of the field, and record producer variable, the back-end values of choices are same. 
The values are getting mapped correctly and showing correctly for the same record, if I open it in the "custom_requested_item_aux" table record. The value is correctly mapping and can update manually to any of three choices (all are visible). It is working fine.

However, the issue is the choice values are not showing for this field in the Form layout of "custom_requested_item" record, where I have added this field in one section. There is no duplicate fields, and back-end values of choices are same.. working in AUX record, but not in "custom_requested_item" record even after both are same.  Also, the mapped values showing as back-end values in "blue color" in form layout not in black color..

Please suggest some solution to this..

Thank you,