I can't login on my droplet, the session will be closed when I try to reset my root pasword.

Thanks. I looked at the other question you linked which included this rundown of what happened:

I enter the password sent by e-mail I enter new password for root twice System disconnected without any errors.

This is not an uncommon issue but because the password reset and login tools are standard to Linux we’re not able easily make a change to make this more accessible and understandable.

Here is the process:

1.) You ssh to your droplet or log in from the control panel using the username “root” 2.) You will be prompted that you need to change your password but this prompt first asks you to enter your current password again. Failing to enter the current password here will disconnect your session. 3.) You’ll now be prompted for your new password. 4.) And you’ll be asked to confirm your new password.

Once this is done you’ll be logged in and your new password will be in use.