phpMyAdmin login not working for Apache + PHP-FPM
Apache + PHP-FPM: When Debian's phpMyAdmin package is installed, there is an alias /phpmyadmin which should work for all vhosts; this is true is PHP is disabled for the vhost or if a PHP mode other than PHP-FPM is selected; if PHP-FPM is selected, the login redirects from /phpmyadmin to /index.php in the document root.