Hello bert and welcome to the forum.
Can we assume that this is not a Microsoft ID (account), but instead a local account and a member of the local administrator's group?
Do you have a second user account on the computer?
Double check the spelling of the user name and make sure it is exact.
Use the "eye" icon in the password box and confirm that your password is being entered exactly as you expect.
Make sure that you are not on the PIN screen (sign in options)
Do you see an option adjacent to the username and password field referencing something like "not me" or "I'm not"?