So now things seem…ok. I had a huge issue with the latest kwin update where I was getting a black screen on boot and lots of crashes. After that I had this issue where if I full screened a video on youtube on my built in laptop display and moved my mouse to the external then back - it would freeze and I would have to hard reboot. Interestingly enough this did not happen if I did it on the external display. I had AMD error messages after. So…I am running all my graphics on NVIDIA and so far there are no issues. Other than I can’t use sway etc.
When using wayland can you try creating folder and file ~/.config/environment.d/90-nvidia.conf
with the content
__NV_PRIME_RENDER_OFFLOAD=1
__GLX_VENDOR_LIBRARY_NAME=nvidia
__VK_LAYER_NV_optimus=NVIDIA_only