Interesting that it refused to boot.

If I have a lower wattage charger connected on booth it shows me that information but I can just press enter to continue. It's just a warning.

Maybe it's a bios setting?

Workaround is of course to boot without a charger connected and then connect it later :)

Oh, refusing to boot at all is evil. I've never seen that.

Sure, you or I would just unplug the charger and run on battery but bad UX decisions like that generate a support call to me from my 95 yr old mom. It should not only warn and continue to boot, it should use whatever power is on offer to reduce the rate of battery drain.