[Wayland] unplugging 2nd screen will cause Qt applications to 100% CPU load due Qtfontconfig

Environment:

Fedora 35
KDE Plasma 5.24.4
KDE Frameworks Version 5.91.0
Qt 5.15.2

While in a Plasma Wayland session, when I unplug the external display from my laptop, some Qt based applications [1] will start using 100% CPU due libQt5Gui.so and libfontconfig.so as you can see in the following "perf top" screenshots.
Running "fc-cache -f -v" did not fix the problem

[1]: like KeepassXC, Amarok, Konsole, Dolphin, etc.