@evb my bad. The nodebb admin interface has a "Save" button that I didn't see so the changes I made were thrown away. I've re-entered the settings ans this time I clicked Save
To fix, first clean the nozzle to look like new from the outside. Next heat up the nozzle to temp and apply pressure to the filament with your fingers, usually this will push through a clog. If you cannot manually push filament through, consider replacing the nozzle or entire hotend.
Reporting back: I have my BambuLab X1C printer setup and have printed with it for about a week. It's fantastic: it's fast, and the prints come out perfectly every time. Truly an appliance: it works with only minor setup straight out of the box. I'd say it's a quantum leap better than my Prusa MK3S, which I guess I should try to sell while it still has value.