Font size device vs Font Size App

For my app, I use the "Classic" theme; to adapt the text sizes (buttons, labels, ..) according to the font size chosen in the device, I try to use the extension TaifunTools" / PuravidaApps.
If the extension works well for ListView, this does not seem the case for buttons and labels (..?).
I attach my AIA test file. Is there something that I am not doing correctly, and why is the number "2" added to the label?
Thank you for your advice and have a nice day
FontSizeExtension.aia (24.9 KB)