I have no idea if this is an XFCE thing or not, so I tossed it in the fray…
After an update, some programs (Eric editor and Shotcut to name two) have huge fonts and rae not usable.
I think those two programs are Qt based. Have you tried changing the font for Qt based applications?
In Xfce this can be done using
qt5ct (Qt5 Configuration Tool) from a terminal window and set the preferred font in the Fonts tab.
Hope that helps!
I owe you a beer!
That helped like a charm!