The last two lines are of interest here. They appear while kwin_wayland is initializing the compositor. The Wayland compositor fails to create a framebuffer , which explains the freeze of the graphic stack you observe.
I can only speculate here, but perhaps KWin chooses the wrong device (NVIDIA drm)…
mar 14 21:43:45 gwerlas systemd[6263]: Starting KDE Wayland Compositor...
mar 14 21:43:45 gwerlas systemd[6263]: Started KDE Wayland Compositor.
mar 14 21:43:45 gwerlas kwin_wayland[6359]: No backend specified, automatically choosing drm
Check ls -l /dev/dri/ and report back.
I’d expect /dev/dri/card0 to be the Intel device and /dev/dri/card1 to be the NVIDIA device.
If that is the case try starting the Plasma Wayland session from a VT using
export KWIN_DRM_DEVICES=/dev/dri/card0
startplasma-wayland
Does that succeed?