解决office365无法登录以及同步的问题

You better need to test them one by one.

Trick1

win + R -> cmd -> regedit -> "path" Computer\HKEY_CURRENT_USER\Software\Microsoft\Office\16.0(this may different)\Common\SignIn, set value data as 0 , where name is SignlnOptions.If don't exist, new key.

Trick2

I went to Settings -> Accounts -> Access Work or School. And I hit "Disconnect" on her company Work or School account. This deletes the saved Office 365 / Azure AD account from the machine.
After that, when I went into Word -> Office Account I see the yellow message below. "Can't display online services. Sorry, we had a server issue and can't display your connected services. Please try again."
When I clicked on Try again, it then pulled up a different looking sign-in window and it walked me all the way through the sign-in process include email address and password. (It also prompted me to add a phone number and a PIN, I think because Azure AD had some new security requirements.)