title: Text in TextFormField goes to vanished
body: <p>I'm designing a layout in which I've a <code>TextFormField</code>. Text in <code>TextFormField</code> vanished. I want text remain on first line.</p>
  <p>This is how it looks when I enter text</p>
  <p><a href="https://i.stack.imgur.com/TG5c8.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/TG5c8.jpg" alt="enter image description here" /></a></p>
  <p>And this is how it looks when I enter more text</p>
  <p><a href="https://i.stack.imgur.com/lfZ71.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/lfZ71.jpg" alt="enter image description here" /></a></p>
  <p><strong>Here is my code</strong></p>
  <pre><code>Container(
              margin: EdgeInsets.only(left: 96, right: 96),
              width: 171.0,
              height: 22.0,
              child: TextFormField(
                keyboardType: TextInputType.emailAddress,
                decoration: loginPageInputDecoration(),
              ),
            ),
  </code></pre>
  <p><strong>loginPageInputDecoration</strong></p>
  <pre><code> InputDecoration loginPageInputDecoration() {
    return const InputDecoration(
      border: InputBorder.none,
      fillColor: fTextFieldColor,
      filled: true,
    );
  }
  </code></pre>