Button Disappears in android

<div class="bar bar-footer bar-we-footer hide-on-keyboard-open" hide-on-keyboard="true"><div class="row text-center" ng-if="!user_id  && !continueAsGuest ">
        <button class="col col-50 button button-dark footer-button-home" ng-click="doLogin()">Login</button> &nbsp;&nbsp;
        <button class="col col-50 button button-we-orange footer-button-home" ng-click="checkGuest()">Guest</button>
    </div></div>

i had above code what is happening in android is when the form is opened keyboard pop up and the login/guest hides. But when i’m done with filling the input fields i’m doing android back then the keyboard close. the button still hides. when i give a tap on screen button shows up. how do i auto get the button when keyboard is closed.