SideMenu header is not fixed while focus the textbox in content in iOS device

I have used the Ionic SideMenu and SideMenu header is move top and hide while focus textbox in iOS device.

<ion-content padding>
  <h3>Ionic Menu Starter</h3>

    If you get lost, the <a href="">docs</a> will show you the way.
**<input type="text"/>**
  <button ion-button secondary menuToggle>Toggle Menu</button>

Please suggest how to resolve it?