Why is my AngularJS directive caching previous values? - angularjs

Question

I have implemented "navbar" in my web application using AngularJS directive. When the user is logged in, it displays the username of the logged in user. But, when I log in as a different user, it still displays the username of the previous user until I manually refresh the window.
Is there any solution to this?
This is the navigation-directive.html
<header class="container" ng-controller="HomeController as vm" ng-init="vm.init()">
<!-- Fixed navbar -->
<nav class="navbar navbar-expand-md navbar-dark fixed-top bg-dark">
<a class="navbar-brand" href="#">ABC app</a>
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarCollapse" aria-controls="navbarCollapse" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="navbarCollapse">
<ul ng-if="vm.isLoggedIn()" class="navbar-nav ml-auto">
<li class="nav-item">
<a class="nav-link" href="#!/homeuser">Home</span></a>
</li>
<li class="nav-item">
<a class="nav-link" href="#!/myappointments">My Appointments</span></a>
</li>
<li class="nav-item active">
<a class="nav-link">Welcome!<strong> {{vm.loggedInUser}} </strong><i class="fa fa-user-circle-o"></i></a>
</li>
<li class="nav-item">
<a class="nav-link" ng-click="vm.logout()">Logout</span></a>
</li>
</ul>
</div>
</nav>
</header>
Below is the navigation-directive.js
angular.module('bbms').directive('mhNavigation', mhNavigation);
function mhNavigation(){
return{
restrict: 'E',
templateUrl: 'angular-app/navigation-directive/navigation-directive.html'
};
}
And in my HomeController I am doing
vm.loggedInUser = response.data.username;
I have copied the relevant part from my home controller