Initial Database connection failing

I’m havng trouble with my very first connection to the MySql database. Here is the excerpt from wp-config.php (with username and password suitably obfuscated and blank lines and comments removed):

define( ‘DB_NAME’, ‘wp’ );
define( ‘DB_USER’, ‘uuuu’ );
define( ‘DB_PASSWORD’, ‘ppppp’ );
define( ‘DB_HOST’, ‘localhost’ );`

I can connect to the empty ‘wp’ database from the host command line with
$ mysql -u uuuu -p
and from a remotely connected computer with the same username/password.

In mariadb when I “show grants” for uuuu@’%’ and uuuu@’localhost’ I see that uuuu has all privileges on *.*.

The host is an iMac running Big Sur, all properly updated. PHP V 7.3.29, a fresh WordPress download, and Mariadb v.10.6.4 and MySql v.15.1.

Any suggestions would be appreciated, other than using MAMP or XAMPP–they don’t meet my mobility requirements.