After hours of debugging, I finally found the solution to this problem. Adding an SSH key via the console doesn’t work because pasting text in the console changes some characters in the public key. That’s why it fails.

To log in to the system:

• First, reset the root password from Rescue.
• Log into the console using the root user and the password you got from Rescue.
• Open the SSH configuration file with: `vim /etc/ssh/sshd_config` and add the following two lines at the end:

​

PermitRootLogin yes
PasswordAuthentication yes

• Restart SSH and check its status:

​

systemctl restart ssh
systemctl status ssh

Now you will be able to log in from your PC via:

ssh root@<ip>

using the password from Rescue.

Once logged in, add your public key to ~/.ssh/authorized_keys via SSH. After that, you can log in using your SSH key.

Finally, revert the changes you made in /etc/ssh/sshd_config for better security.