No access to Network Admin after running Network Setup in new WP install

I’ve installed a completely new WordPress and want to have multiple sub-folders off it e.g. greatsite.com, greatsite.com/school, greatsite.com/services, greatsite.com/shop, etc.

I followed the step by step instructions at https://www.elegantthemes.com/blog/resources/the-complete-guide-to-creating-a-wordpress-multisite-installation

1) I added

/* Multisite */
define( 'WP_ALLOW_MULTISITE', true );

to wpconfig.

2) In WordPress I was then able to see Network Setup and I followed the process of adding code to .htaccess and wpconfig files.

But then when I log out and go back into WordPress there is no Network Admin option anywhere. And the Network Setup option that was under Tools has disappeared.

I’ve tried reinstalling WordPress 4 times and going through this process again and again, each time with the same result, and with no plugins installed – just a bare version of WordPress.
Hope someone can help!