Unable to edit field from Service Request contact relationship

Summary

Unable to edit field from Service Request contact relationship

Content

Objective: While adding contacts to a service request, we have to specify what role that contact plays in the service request.

Steps followed:

1. Created role field in Contact member object (under SR object)

2. Exposed it in the Contact list page (subtab under SR page)

3. I can add a contact or create a new contact from the contact subtab, but for none of them, this field is editable.

Basically, unable to edit the field that is present form the Interseciton object b/w SR and Contact.

Attached screenshot. 

 

Quesiton : How to mention the role of the contact for a SR?