Still not seeing any other complaints here about failures to login... (to be fair, there was one, but they had the password wrong). If you are determined to ignore Support and have alreay tried all the obvious fixes, I'll leave you to your righteous misery.
(It's also helpful by the way to say in your initial post what you may have already tried to fix your situation, because it saves us time repeating dumb advice that you're going to ignore anway...)
Do let us know if/ when you find a fix...