Thank you for writing.
The font size of the Title and the font size of the Count are different and applying a new font size through style changes only the font size of the Count as you have correctly observed.
If you need to change the size of another element of the hub tile, you need to edit its ControlTemplate.
You can easily extract the default style by choosing Edit Template -> Edit a Copy
after you right-click the HubTile in VisualStudio's designer. Then you can locate the element named "PART_Title" in the extracted style and change its properties according to your preferences.
I hope this information helps.
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