Ionic 3 radio-group not binding selected item

So I have a radio-group ion-list element, thus far it works given the following:

<ion-list radio-group [(ngModel)]="selectedAddress">
    <ion-item *ngFor="let address of userAddresses">
        <ion-label>{{address.Street}}, {{address.Suburb}}, {{address.City}}</ion-label>
        <ion-radio value="{{address.RefAddress}}"></ion-radio>
    </ion-item>
</ion-list>

The data I used to populate this is a collection of Address objects implementing the following interface:

export interface Address {
   RefAddress?:number,
   Street:string,
   Street2?:string,
   Suburb:string,
   City:string,
   Province:string,
   Country:string
}

This works without a hitch, I can select items and my ngModel is populated with with whichever address I chose. Now however, I cannot set the selected item in code when the user opens the page again to edit a previous selection and the list is reloaded, i.e I populated the selectedAddress with an address item when the page is loaded:

if (this.navParams.get("Address")) {
    this.selectedAddress = this.navParams.get("Address");
}

I made sure to only call the above function once all the items are loaded to the list first and with debugging I can confitm the selectedAddress prop is being set. What am I missing?

Can you confirm that what is being passed through NavParams as “Address” is a scalar number corresponding to the RefAddress of something in userAddresses, as opposed to an Address object?