Starting QT apps via thunar differs from starting them in other ways


after the recent update of my office desktop computer, I now experience a strange behavior.

My desktop settings are 4K resolution with 2x scaling and adwaita dark theme applied.

When I start any QT program (kate, kile, qpdfview, etc.) via thunar (it doesn’t matter wether left- or right-click), it starts with the light theme and a tiny 1x scaling.

The same programs display themselfs in the correct manner if I start them via Start-Menu, the terminal or even via a different file browser (PCManFM).

Where can I look to determine why and how thunar starts them differently?

Thank you all in advance for your help


PS: thunar Version: 4.18.6, PCManFM Version: 1.3.2

I have neither of these programs, but i checked which of my stuff is dependent on qt5-base. So i just double clicked /usr/bin/audacious and it looks normal (Dark and large enough). I am however on FullHD with 120 DPI font setting, the scaling through the “Display” settings was too large and buggy for me. But that cannot reset the theme anyways.

I was going to mention QT styling under a GTK desktop … but if it is sometimes working that may not be the issue. link anyways…