Created attachment 125437 [details] gtk3 configuration file. Relevant line is number ten. SUMMARY When a font with a space in its name is selected, missing comma after font name in generated GTK configuration files causes the wrong font to be applied. STEPS TO REPRODUCE 1. In font settings, select a font that contains a space in its name e.g. Roboto Condensed. In 5.17.90, it will be applied to GTK. 2. Open a GTK application. OBSERVED RESULT GTK applications display Roboto font. EXPECTED RESULT GTK applications display Roboto Condensed font. SOFTWARE/OS VERSIONS Linux/KDE Plasma: Arch Linux, using Kde-Unstable repository. (available in About System) KDE Plasma Version: 5.17.90 KDE Frameworks Version: 5.66.0 Qt Version: 5.14.0 ADDITIONAL INFORMATION Putting a comma after the font name and before the font size fixes the problem.
Created attachment 125438 [details] gtk2 configuration file. Relevant line is number 7.
It seems that I uploaded files that were generated by Lxappearance which I used to fix the issue. Will upload the correct files.
Created attachment 125439 [details] the correct gtk2 configuration file
Created attachment 125440 [details] the correct gtk3 configuration file
*** This bug has been marked as a duplicate of bug 380980 ***