Windows searching for a PIN

I played outdoors in city park today. When I turned on my Surface Pro 8, no sound came out, even though all the connections were good. I rebooted the PC and almost immediately, Windows started asking for a PIN and would not budge any further towards readiness. Eventually, I turned on my phones mobile hotspot, Windows saw the connection and the PC booted up without further ado. I got sound at that point.

My question is, why did the PC do this? Normally I get a clean boot up eventuating in sound for GP. I have had this happen two or three times recently, and am wondering what a fix might be. Cheers for any helpful advice.

P.S. I was running on a mains level power pack. Could this have anything to do with the problem?

This is not really a Gig Performer issue. A trivial google search will take you to Microsoft support where apparently this is a well known thing addressed on their forums, e.g.