Angular language service doesnt intellisense _variable

Question

I am using Visual Studio Code for Angular 5 project I have converted my post JSON data into typeScript file like

//interface class of post data
export interface Client {
  ctm_id: number;
  firstname: string;
  middlename: string;
}

//interface class of post data
export interface ClientContact {
  phone: number;
  alternate_phone: number;
}

//interface class of post data
export interface ClientPostData {
  client: Client;
  clientContacts: ClientContact;
  clientMedical_info:Clientmedicalinfo;
}

// and declared in component class like     
export class FormComponent implements OnInit {
  public model: ClientPostData = <ClientPostData>{};
  public ffirst_name:string;
}

I have installed Angular language service to get suggestions for variables from the interface.

When I type f it suggests firstname in html.but it doesn't suggest clientMedical_info when I type model.(dot).It suggests model.clients and model.clientContacts

How can I get suggestion of client_contact when I type model.(dot)