SomeGuy just save my life with OpenSSH on windows. I spend almost a day trying to configure public-key auth with no success.
Then I found your post about the enconding of authorized_keys e apply it to administrators_authorized_keys on C:/ProgramData/ssh/ .
I save it on UTF-8 with vscode end finally I could login without password.
OpenSSH publickey login on windows is very obscure... even with DEBUG on the sshd service dont tell why it is denying the key.