I also have this problem. I solve it by using another browser that I have not stored the password in. But I agree that a fix would be nice.
To confirm, the problem is:
I have saved my password for the WordPress admin login using Safari or Chromes feature to do so. When I go to the Easy WP SMTP settings the username and password fields are yellow and prefilled with the username and password for the admin.
I inspected the form and it does have a unique name easy_wp_smtp_username. Perhaps giving it an ID might help.
Thanks