Having the same issue here, has anyone figured anything out? maybe it is a misspelling or something we don't expect??

Hi, had the exact same problem before. I pretty much gave up and was trying random things, disconnecting battery, holding power button, plugging in two USB C chargers (it was only accepting 5V too, so I found some power supplies that would supply large amperages (~4A iirc)), then held down power + reset simultaneously... somehow it booted up and started accepting 20V again, and has been working fine since!

What did you up doing, Zixu? Did you figure out anything regarding your problem since?