I have seen, on an older Dell, that if the main battery is exhausted, beyond shutdown. Then the computer would not run off the mains, or charge the battery. Replacing the battery fixed the problem. I could hypothesize that unplugging the battery might allow it to run off the mains.
Is it possible that when you stopped working last, you just closed the screen, instead of doing a full shutdown from the OS?
One could also hypothesize that some hangs are from some websites who have software that insists on monitoring connections, and will not advance without that ability. But one would think that would clear on a reboot, and clearing some histories. But that is a different issue.
Is there an option with a Librem where it could be booted from a USB version of another Linux. I am guessing you did try to look at BIOS/EFI?