When you change a password, a popup is presented with few suggested password. Select one and it will become the new password.
Once you have selected the password you wish, hit accept and this will be applied.
This exits the password change session. The old password is left in place.
This exits the "Automatically generated password" dialog. Another popup shows up and you can enter the password of your choice.
This calls the password generator again, so new passwords are proposed. Use this button until you get a password you like...