Regarding the problem with OpenMW-CS (See software forum, https://forum.manjaro.org/t/openmw-cs-stopped-working-qt5-15-xfce4-problem/)
It seems that QStatusBar fails on XFCE4. The same code works fine on Gnome, and has worked previously on XFCE4. Could there be a regression somewhere in the XFCE4-code or something related to Qt?