Hello and welcome to the forum
Please describe more of what exactly your doing.
Do you have any sd card inserted when booting?
When was the last time you updated?
Are you talking about laptop screen or wheel external screen? If it’s about external screen then the usb-c to hdmi drivers are experimental and not stable so it has nothing to do with Manjaro OS it is more of kernel issue.
Please share detailed information for further understanding.
It is available in the repo, we maintain bsp and mainline uboot so users can switch to their preferred uboot.
sudo pacman -S uboot-pinebookpro-bsp
Will install the bsp uboot but you will have to flash it manually by following the instructions printed after installation.