On v2 after installing some packages and autoremoving some “unused” packages I could no longer launch xwayland.
This thread had the fix, apt install llvm-11*:
The grey screen issue happens for me occasionally, and I have restart and try again. In my limited testing it does seem to happen more often on v3 than v2.
Is there a reason you are using mkimage.sh instead of just downloading a prebuilt image?