Same here.
SAtarting until sddm is okay, then a lot of flickering is happening on the screen. plsma is opening here, so no freeze, but unusable due to flickering.
A partial workaround is to open Screensettings (Anzeige) and choose a smaller resolution, confirm, and then again the right solution (confirm agein).
Programs work, computer is usable, but plsama is dead. No working Kmenu or working icons.