I'm having similar issues. Surface Book 2 is connected to charger but it does not light up nor charge. Only solution is to reboot. Sometimes I have to do a hard reboot to restore charging. Happened twice in the last three days now. Rebooting solves the problem so I don't think it's a charger issue even though I think the Microsoft branded chargers and every replacement charger I've purchased in the last couple of years suck and die.
I'm going to install this update after I post this and see if the problem is solved....not holding my breath.
Surface - System - 1.82.139.0