Cannot Login to even fresh new WP installs?

Hi, I have a problem logging into fresh new WordPress installs.
I have a lot of wordpress experience and have built many sites. The other day I could not login to one of my sites. And so I tried a few different methods to try to get back in to my dashboard. Backing up DB, restore, add new user, deactivate plugins folder, create entirely new WordPress folder and imported DB and I still cannot login to any of these methods I tried. I am stummped as to why after submitting user and pass, it goes back to the login screen. It does not tell me my password or user is incorrect. It just redirects back to wp-login screen. Any ideas what may be the issue?