I am the administrator of a group of 50 PCs, with Windows 10, who have signed Office 365 essential licenses. I inserted all PCs in AD Azure basic version. I connected the PCs with the domain in Azure AD. With this operation some very strange things happen:

1) Local users disappear in the login window of the PC, only the last Office 365 user who logged in and "other users" appears. With "other users", you can only log in with another Office 365 user. You can no longer log in with local users who have not been deleted, but are listed among users;

2) I can administer the PC only with the Office 365 Administrator and not with the local Administrator;

3) if there is no network connection, the PC is unusable. It is only possible to use the PC connected to the Internet and to Office 365 users. It is not possible to use the PC locally to work for example with Autocad;

4) By removing the PC from AD Azure, the PC returns to the local but at the login I do not see the local users anymore and I have to manually recreate them by copying the configurations.

Can anyone suggest to me how to see both local and Office 365 users at the same time as the Windows 10 login? Or how to use local users or Office 365 users?

On previous versions of windows, at login, by double-clicking ctrl + alt + delete the administrative user appeared, which normally was hidden. I tried but this function on Windows 10 does not exist.