Change checkbox state from change event

When my checkbox is checked, a dialog is opened and when I click cancel, the checkbox should be unchecked.

I can't get this to happen.

The checkbox should be set to its previous state if "no" is selected on the dialog (see the if statements).

However, it seems as though setting the model for the checkbox, $scope.canSupportAccess, has no effect on the checking of the checkbox inside this function.

I have tested whether or not $scope.canSupportAccess is able to update the checkbox at all, by initializing it with true and false, and can see that it does indeed check or uncheck the checkbox.

I noticed I have to pass in canSupportAccess as an argument to the function, because $scope.canSupportAccess is not updated inside updateSupportAccess() even though $scope.canSupportAccess is the model and updateSupportAccess() is triggered when the checkbox changes.

Why does $scope.canSupportAccess have no effect inside the function, and how can I update the checkbox inside the updateSupportAccess() function?

Is this by design, to avoid the updateSupportAccess() being called recursively forever? If so, what is the work around?

Here's my code:

export default function (app) {
    app.controller('userDetailCtrl', [
        'shell',
        '$scope',
        function (shell, $scope) {
            $scope.canSupportAccess = false;
            $scope.updateSupportAccess = function (canSupportAccess) {
                if (canSupportAccess) {
                    shell.confirmBox('Allow Access',
                        'Allow access?',
                        'YesNo', true)
                        .result
                        .then(function (result) {
                            if (result === "yes") {
                                $scope.canSupportAccess = true;

                            } else {
                                $scope.canSupportAccess = false;
                            }
                        });
                } else {
                    shell.confirmBox('Remove Access',
                        'Revoke access?',
                        'YesNo')
                        .result
                        .then(function (result) {
                            if (result === "yes") {
                                $scope.canSupportAccess = false;
                            } else {
                                $scope.canSupportAccess = true;
                            }
                        });
                }
            }
        }]
    );
}

and the HTML:

<input type="checkbox"
       id="supportAccess"
       ng-change="updateSupportAccess(canSupportAccess)"
       ng-model="canSupportAccess" />
<label for="supportAccess">
    Allow access.
</label>