When running PHP version 7.3.x or older, set MySQL 8 Server's default password plugin to mysql_native_password or else you will see errors.
In the "core\mysql\my.ini" file, change: authentication_policy = caching_sha2_password to: default_authentication_plugin=mysql_native_password
Using phpMyAdmin, isolate DB User(s) and Host(s) that were created with caching_sha2_password, and change the plugin type from caching_sha2_password to mysql_native_password:
ALTER USER 'pma'@'localhost' IDENTIFIED WITH mysql_native_password BY 'root';
ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY 'root';
Hope this helps!