That article links only the common connection errors, not phpMyAdmin errors. Try removing cookies or cache or login to the Panel in incognito mode to prevent ERR_TOO_MANY_REDIRECTS errors while logging on phpMyAdmin, and make sure you clicked on “Show/Hide” to show the password of the hosting account, to not put asterisks while copying the password.
This is a more commonly occurring problem with database permissions which tend to get corrupted once in a while. If phpMyAdmin shows a redirect error and the PHP code shows Access Denied, that’s usually a good indicator.
I can get database permissions reset, which generally fixes both issues. But recreating a database probably works as well.