Urgent help: IOS App Page looks difference between Xamarin Studio Vs Visual Studio 2015 compiled

I have been stuck here for a long time, couldn't find any reason

I have a simple page with image and long text.
The top part are a image on left, on right from top are a label with multiple line of long text, then a image and text.

Below top part are different label on StackLayout.

I run the simple app on Windows 10 VM inside of mac with visual studio 2015.

No matter how I adjust the layout, the text below the top part will overlap with the image, and the top text will be cut a little.
So I tried the same page on Xamarin Studio(Mac), it display perfectly as I expected.

Why are the Xamarin Studio compiled result different from visual studio? Or is there anything wrong with my Visual Studio or anything else?
Please help me, I have been pulling my hair.

I have attched two images,TestApp.TestPage.axml/cs and simulator screen copy.
The following is the page layout:

    <StackLayout Orientation="Horizontal"
                 HorizontalOptions="StartAndExpand">
      <Label Text="Number："
             HorizontalOptions="Start" />
      <Label Text="50000"
             HorizontalOptions="FillAndExpand" />
    </StackLayout>
  </StackLayout>
</ScrollView>
<StackLayout VerticalOptions="EndAndExpand">
  <StackLayout Orientation="Horizontal">
    <Button Text="Button 1"></Button>
    <Button Text="Button 2"></Button>
    <Button Text="Button 3"></Button>
  </StackLayout>
</StackLayout>