Unreal Engine 4.18 + KDE = Very Slow/Lag

The Unreal Editor menus are very slow,it looks like the menus are lagging, it takes around 3-6 sec to move from one menu to another.
The FPS from 120 goes down to 20-0 FPS and freezes if I am moving the mouse continuously and a bit quickly around the menus.

(I am using Plasma with a high end pc, Nvidia 1080Ti and AMD Threadripper 1950x)

I tested also Unity Engine and is working fine a bit of lag there as well but is unnoticed.

With another DE (tested MATE) is working fine no delays and not lag at all.
I have posted this problem to unreal engine and KDE forums but I guess this maybe has to do with Nvidia Drivers?

cheers

Hi,

welcome to the “nvdia and kde don’t work fine together atm” story :(.

Did you check dmesg if you see any NVRM: Xid whilc you see the freezes ?

I am asking cause there are some threads in the forum already about kwin/kde + latest nvidia issues, including mine (switched to gnome/xfce atm which work fine) whihc show nvrm xids in dmesg.

Maybe you also hot that issue.

Many thanks !
Christian