MigratingfromTiki253to28x
Most of the fonts in the themes were changed from web fonts to system fonts, using this guide for replacement, to avoid potential privacy issues and to speed up initial page loads. If you prefer the web font, it could be reinstated with some custom CSS in the Tiki Look & Feel admin page.
(I'm not aware of a problem with dropdown boxes for dates overlapping so maybe someone else can comment on that.)
-- Gary