@Henry: I found a painless way of resolving this was to physically log in to the Windows laptop, using your password (ONLY, and NOT your face or fingerprint or PIN), and then log out (and if possible, then reboot). Thereafter, with the Windows laptop up and running, go onto your Mac, fire up RDP, and use it to connect from Mac to Windows as you would expect to. It should work.
It seems that there is a caching issue, such that if the last/previous time you directly logged into Windows was via biometric or PIN (or other non-password) credentials, then the RDP receiver/server on the Windows laptop will refuse your username/password connection attempt via RDP. (It's as if Windows' RDP server is comparing your remote authentication attempt against the previous physical authentication, and refusing if they don't match...)
Best wishes. Hopefully this helps as well:
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