Comment # 17 on bug 1185048 from Fabian Vogt

Apparently Qt 5.14 added yet another opt-in switch to enable the needed
behaviour. Does it work with QT_USE_PHYSICAL_DPI=1?

I filed a bug upstream (https://bugreports.qt.io/browse/QTBUG-93454) and made a
patch to restore the previous behaviour. Please try libQt5Gui5 from
https://build.opensuse.org/package/show/home:Vogtinator:boo1185048/libqt5-qtbase.