Filter apply button font

Hi,

I recently discovered that the font family of the filter apply button is set to Segoe MDL2 Assets (by using the visual tree explorer). Possibly this is an error in the original resources file from Telerik. I also thought I had made a mistake with the localization, but even a brand new VS solution does not fix the issue.

So I decided to change it using 

but this doesn't change the font family at all.

Please indicate me a way to reverse the apply button font family to Segoe UI (default font).

Thanks.