xampp mysql用户只能在没有密码的情况下工作

I'm developing a PHP/MySQL site locally using XAMPP. In my PHP connection file I had a user 'root' with an empty password, and it worked fine so far. However when I try to add a new user in XAMPP with a password (that matches the live site configuration), the site stops working, producing 500 error. I tried and checked everything, but I couldn't figure out what the problem could be. What should I still check?

Step 1: Locate phpMyAdmin installation path.

Step 2: Open phpMyAdmin/config.inc.php in your favourite text editor. Copy config.sample.inc.php to config.inc.php if it's missing.

Step 3: Search for $cfg['Servers'][$i]['auth_type'] = 'config';

Replace it with $cfg['Servers'][$i]['auth_type'] = 'cookie';