Textbox is becoming readonly in flyout, UWP store app
<p>In button flyout I am using one usercontrol inside that I have textbox. when running the app the textbox is appearing as readonly, don't know why I am getting this issue. nowhere I am setting readonly.</p>

<pre><code>&lt;TextBox Margin="2" Height="32" 
                     MaxHeight="60"
                     TextWrapping="Wrap"
                     HorizontalAlignment="Stretch" 
                     TextAlignment="Left"
                     Text="ramesh"
                     Style="{x:Null}"/&gt;
</code></pre>