TextInputLayout hint issue when handling FocusChange event - android-edittext

Question

My app has a couple of EditTexts with a TextInputLayout wrapped around them. This works fine in most cases, but when I attach a handler to the FocusChange event of the EditText, the hint fails to animate.
I found this issue on the android forum, but he uses the OnFocusChangeListener. Proxying the call should not be necessary with events, right?
Any ideas on this issue? Is it a bug in the Xamarin android design support NuGet package?
Thanks in advance
Layout code:
<android.support.design.widget.TextInputLayout
android:layout_width="0dp"
android:layout_weight="1"
android:layout_height="wrap_content">
<EditText
android:id="#+id/txtProductCode"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:maxLines="1"
android:inputType="textCapCharacters|textNoSuggestions"
android:hint="Artikelcode" />
</android.support.design.widget.TextInputLayout>
Fragment code:
public override void OnStart()
{
base.OnStart();
txtProductCode.FocusChange += txtProductCode_FocusChange;
// ...
}
void txtProductCode_FocusChange(object sender, View.FocusChangeEventArgs e)
{
if (!e.HasFocus)
txtDescription.Text = GetProductDescription();
}

Answer 1

From this post this i found my solution for the problem.
As stated in the post it's kind of a workaround but i think this should work in the new design library version 22.2.1 but for me the problem still persists.
Here is my code based on the mentioned post:
final View.OnFocusChangeListener userNameEtFocusListener = userNameEt.getOnFocusChangeListener();
userNameEt.setOnFocusChangeListener(new View.OnFocusChangeListener() {
#Override
public void onFocusChange(View v, boolean hasFocus) {
userNameEtFocusListener.onFocusChange(v, hasFocus);
if (!hasFocus){
userInfoValidator.checkUserNameAvailable(userNameEt.getText().toString());
}
}
});