I've just tested again in 14.0rc5 and I encountered many times this gam_server deadlock.
https://bugzilla.gnome.org/show_bug.cgi?id=667230
It prevents KDE apps from starting once a while and appears more frequently when I open multiple applications quickly.
The patch has been accepted apparently but is still not part of an upstream release.
Can it be fixed before 14.0 is released ? (will prevent some KDE apps hanging at start report)