Just got back from dropping the car off at the dealer. They said it looks like some clock spring sensor contraption in the steering wheel is the likely culprit. Apparently this was a problem with some of the early non-EV XC40s a couple of years ago. Parts on order, should be able to pick it up Wednesday.
Update: Dealer told me the Airbag was intermittent and must be replaced. First said, there were no Airbags in the USA available for repair and would have to be shipped in from Europe. Then, got a 2nd call, Volvo corporate found one on the East Coast and will expedite it in. Should get the car back on Wed.
Yesterday, the Service Manager called me and said, "Uh no, we don't have the right part in the US. So, it will have to come from Sweden". Crap. He said about 2 weeks. Not holding my breath. But, at least they got me a Loaner.
I had this problem show up once. It happened almost immediately after plugging in a phone, having a phone wireless charging, having a seat heater on, and having an inverter plugged in for my laptop. Upon restarting the infotainment, letting the car reat, and not plugging in the inverter again I’ve never received this again. I think it was my inverter, or just too much power that it interferes with something. Will keep an eye out.