Quick question on model binding.

I am buiding a custom dashboard in the backend (based on Tims People tree - https://github.com/TimGeyssens/UmbracoAngularBackofficePages/blob/master/TestSite/App_Plugins/Example/backoffice/peopleTree/edit.controller.js)

I am not using a full person object like the example but a simple string that is on my model - searchterm.

I have textbox and it display the default i set in the model. When i edit the textbox the value on the scope is not updating but if i add a second textbox and set it to the same model variable it updates as i type.

The only way i have gotten to update the model value on the scope is to add a change event on the textbox, pass in the model value from the view and update the scope!

Driving me nuts as to why!! Any ideas??

Here is the bit from the view

 <umb-control-group label="Search Term" description="Enter serach term'">
                    <input type="text" class="umb-editor umb-textstring" ng-model="searchTerm" ng-change="changed(searchTerm)" required />

                    <br/>
                    scope = {{ searchTerm}} ..
                    <input ng-model="searchTerm"/>
                </umb-control-group>

Here is the controller:

angular.module("umbraco").controller("MemberLocate.MemberLocateEditController",
function ($scope, $routeParams, memberLocateResource, notificationsService, navigationService) {

    console.log('scope triggered');

    $scope.loaded = false;
    $scope.members = {};
    $scope.searchTerm = "roger";
    $scope.searchType = "AccountNumber";

    if ($routeParams.id == -1) {
        $scope.searchTerm = "test 2";
        $scope.members = {};
        $scope.loaded = true;
    }

    $scope.loaded = true;
    $scope.searchDone = false;

    $scope.changed = function (val) {
        $scope.searchTerm = val;
        console.log('val=' + val);
        console.log('changed' + $scope.searchTerm);
    };

    $scope.search = function () {

        console.log('search term=' + $scope.searchTerm);
        console.log('search type=' + $scope.searchType);

        memberLocateResource.findByUsername($scope.searchTerm).then(function (response) {

            $scope.members = response.data;
            $scope.memberLocateForm.$dirty = false;
            $scope.searchDone = true;
            //navigationService.syncTree({ tree: 'peopleTree', path: [-1, -1], forceReload: true });
            //notificationsService.success("Success", person.firstName + " " + person.lastName + " has been saved");
        });
    };     
});