Can't ssh to cygwin after switching sign-in to Windows Hello PIN

[Henry S. Thompson]

Running cygwin 3.2.0-1 on Windows 10 Pro 21H1

Since changing my login from local User to Windows Hello PIN, I can't
ssh in to my machine using a password:  neither the PIN nor my old
password work:

  1) If from my machine I do
          ssh -o PreferredAuthentications=password localhost
     or
          ssh -o PreferredAuthentications=password [me]@[host]
     or
          ssh -o PreferredAuthentications=password U-[HOST]\\[me]@[host]

     I get "permission denied".

  2) If I try any of those from another machine, it hangs (but works
     w/o the "-o PreferredAuthentications=password", i.e. using a
     key).  By 'hangs' I mean that having typed the PIN and Enter,
     nothing happens, including no output if I include -v -v -v.

     Weirder still, if I try using strace, communication happens and I
     get "permission denied"

I have reinstalled openssh, removed the cygsshd service, re-run
ssh-host-config and restarted the service to no avail.

I only need password login to install new keys, and obviously there
are workarounds for that, but if there's just something I'm missing
I'd like to fix it.

Are there other things I need to worry about having switched to using
a PIN?

Thanks,

ht
-- 
       Henry S. Thompson, School of Informatics, University of Edinburgh
      10 Crichton Street, Edinburgh EH8 9AB, SCOTLAND -- (44) 131 650-4440
                Fax: (44) 131 650-4587, e-mail: ht@inf.ed.ac.uk
                       URL: http://www.ltg.ed.ac.uk/~ht/
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