Created attachment 875326 [details]
Default KDE-style file picker in Firefox runs under XWayland and does not
respect scaling

The native KDE-style file picker in Firefox uses XWayland on default
Tumbleweed/Plasma installation. That is not a huge problem in itself, but the
XWayland picker does not respect the scaling settings.

However, I noticed that after installing SwayWM in addition to KDE Plasma 6,
Firefox switched to the Wayland file picker.

Removing SwayWM and its dependencies breaks the file picker again.

After investigating the issue, I discovered that the issue goes away if I
manually install libqt5-qtwayland.