React Admin: <ReferenceField> on foreign key fetches the data but does not render child

I am using react-admin 3.1.1

I have one to one relationship between employee and user through email.

I am using graphql on backend.

Here is the code:

<ReferenceField disabled
        label="Registered user"
        source="email"
        reference="RaUser"
        link="show"
      >
        <FunctionField  render={record => {console.log('record', record); return `${record.first_name} ${record.last_name} - ${record.email}`}}  />
      </ReferenceField> 

I can see in the network tab that the request goes through and there is data. However, the reference field is not rendering any children I was trying to console log data in render function in FunctionField but the console.log is not even getting called.

Can somebode help me what to do in order to make it work?