Problem with the 'right menu'


I am having an issue where my right menu does not do well in responsiveness. Everything looks fine on a desktop, but in smaller devices the a-tag of “Log out” does not show. Anyone know what I am missing? Tried a lot of different variations.

<!-- NAV-MENU -->
<div class="ui inverted segment">
<div class="ui inverted massive stackable menu">
    <div class="header item">
        Website Name
    <a class="item" href="index.php">Home</a>
    <a class="item" href="#">Name</a>
    <div class="right menu"> <!-- RIGHT-NAV-MENU -->
         <a class="item" href="mypage.html">My page</a>
         <a class="item" href="logout.html">Log out</a>
    </div> <!-- RIGHT-NAV-MENU END -->
<!-- NAV-MENU-END -->