The basic Questions
3) Did you compile fbcon into the kernel, or compile it as a module and loaded
it? First make sure you have CONFIG_FRAMEBUFFER_CONSOLE enabled in your kernel
configuration. If it is a module (it is called fbcon.ko), make sure it is
loaded. Otherwise activating KMS will make your console screen unusable, but
your system should still work otherwise, including X.

-> Maybe NO, i use the kernel as i got it. so:
sudo modprobe fbcon

modprobe: FATAL: Module fbcon not found in directory
/lib/modules/5.1.0-1-MANJARO