Defining Shell.TitleView while preserving the title text of tabs in shell, but seems showing in a different font

[Cfun1]

I am defining a custom Shell.TitleView in a way to preserve the Tab/Page title of my ContentPage as follow:

<Shell.TitleView>
    <Label Text="Page2" FontSize="20" VerticalTextAlignment="Center"/>
    <!-- rest of my TitleView irrelevant in this question-->
</Shell.TitleView>

For clarity:

• 1st Tab: using my custom Shell.TitleView.
• 2nd Tab: using default Shell.TitleView.
• I am not using any style or custom font just using the empty template project for shell flyout.

The issue here is that the generated title by the default Shell.TitleView (in the second Tab) is different from mine (the difference is more noticeable when you navigate from one tab to the other than in screenshots), at first I thought it was a matter of combination between FontSize and FontAttributes="bold".

What is causing this difference? FontFamily? How to make it same?

EDIT

<Shell.TitleView>
   <Label Text="Page2" FontSize="20" VerticalTextAlignment="Center" FontAttributes="Bold"
               Opacity="1" TextColor="White"/>
</Shell.TitleView>

Updated question and discussion in: Defining Shell.TitleView while preserving the title text of tabs in shell, but seems showing in a different font