After over a month, I’ve updated Manjaro (with yay) on my PineBook Pro. In the log, I saw a message concerning updating u-boot. I followed the instructions (I did that a few times in the past without problems). Reboot. The result is that u-boot detects Manjaro, but then the screen stays blank. Now, I cannot even boot from SD or USB (as I was able to do in the past).
It’s boot firmware. There’s a reason why we don’t flash it for you.
As I just pushed an update that has been tested to work, you need to reflash the new one when your mirrors syncs in the new one for your updates. If that’s not possible for you to access, you need to disable the eMMC by the eMMC switch on the main board, then you can boot from the SD card and reflash a working u-boot to eMMC.