Edit: After half day, my wife’s Mac started having the same problem. I have then applied the solution that I found in the Apple
Use SSH to Log In to an Account in Mac OS
To log in to an account via SSH, perform the following steps:
1. Type this command into the Terminal:
user@localhost: ssh USER@HOST_NAME –pPORT
USER: Name of the user for which you are going to establish the SSH connection.
HOST_NAME: Name of the host/IP address of the server that will be connected to.
PORT: Port for the connection.
2. When you press Enter, the system will ask you to enter the password for USER.
3. Having entered the password, press Enter again, and you will be successfully logged in.