I have had this happen to me on a pixel 8. It will go into charging mode, then it will attempt to boot, get through the yellow ! screen, past the Pixel screen, and hit the GrapheneOS logo and then die. Or, sometimes it will boot completely, then die moments after it fully boots.
I use those magnetic plug chargers or wireless chargers hooked up to a Chargie, which slows the charge rate down. It doesn't happen with just the magnetic plug, which is able to do fast charging (but I try to avoid that, too, because that can also shorten battery lifespan).
I have to do the pause trick whenever I drain the battery, too. I try harder to avoid it, now; I didn't know draining could damage the battery, I thought it was only charging over 70-80% that would hurt it. Now I try to keep it in the 20-80% range.
Graphene devs say their battery management avoids battery damage, buuuuut so does Samsung and iPhone and Pixel and blah blah blah, and if GOS isn't able to determine if the battery is charged enough to boot without re-draining the battery...
Well, I prefer to err on the side of caution.
Tbf, that is probably not GOS's fault, it might be AOSP or maybe even Pixel Hardware. ¯\_(ツ)_/¯
It'd be cool if there was a way to designate some dead band on either end of battery charge level. A Chargie can protect against high charge and charging the battery to high temperatures, but it'd be nice to do that in the phone's settings... And also to make it shut off if it drops below a user-designated level, too, and not turn on again until it reaches above a certain charge level, too. 1% tends not to be enough, 2% is barely enough if you don't do anything, 5% is probably safe if you plan to go right back to actually using the phone.
Unfortunately, from what little I know, this requires uh... ADB? Root? Bad stuff. Bad stuff that GOS pretty much if not always advises against... stridently.