My admin users can't login to the admin back-end of our (IIS) WordPress site. After login they are simply redirected to the homepage.
I've tried every solution I can find on Google. I've tried on Chrome, Firefox, Edge, IE. I can currently login in Chrome, but not any other browser. I don't even want to logout in Chrome in case we are left with absolutely no admin access.
How can I even find out what the actual problem is? Setting WP_DEBUG does nothing.
Please help!