what graphic card and driver do you have
some integrated intel need uxa acceleration
so if you use an intel chip in
/etc/X11/xorg.conf.d/20-intel.conf
set (create the file if it does not exist)
Section "Device"
Identifier "Intel Graphics"
Driver "intel"
Option "AccelMethod" "uxa"
EndSection
if you have an nvidia chip, nouveau does not work well with plasma 5 use nvidia’s propitiatory driver
https://en.opensuse.org/SDB:NVIDIA_drivers#Easy_way_to_get_NVIDIA_drivers
if that’s an optimus laptop use bumblebee with nvidia (not nouveau) and the intel acceleration fix
(I’m not sure about this but if uxa is needed on intel only chips it should be needed on hybrid systems too)
https://en.opensuse.org/SDB:NVIDIA_Bumblebee