I have exactly the same experience, basically got locked out of my Surface Book as I only use Azure AD logon, so rebuild and back to 18323 and I can logon with my password, Hello keeps saying it has to have a pin, but that is how I set it up. And to add
to this, my Office 365 account cannot be added to Outlook as it fails with CAA5004B, and mail keeps prompting me to fix my account with the same result of CAA5004B.
I have reverted to using outlook.office.com for email and am hoping this is a build issue and the next update fixes it. Thankfully everything is stored in a few onedrives.
Also my Windows Hello and PIN worked fine for a day or so after the rebuild, but now both don't work, so make sure you have a second account to logon or be prepared for yet another rebuild.