Getting 404s with directory-based multi-site

I have just installed Grav 1.0.10 on a Raspberry Pi running Apache 2.4.10 and cannot get subdir-based multi-site to work. Default single site works perfectly.

My document base is /var/www/html/and I unpacked grav in /var/www/html/grav, access to the default page with http://myself.dyndns.org/grav is no problem.

I created a directory /var/www/html/grav/user/sites/whatever and copied the default dirs config, pages, plugins, themes.

The setup.php from the current documentation is in /var/www/html/grav, but when I attempt to access http://myself.dyndns.org/grav/whatever I get a grav-generated 404 page.

In .htaccess tried both

# RewriteBase /
RewriteBase /grav

Here is the setup.php:

<?php
/**
 * Multisite setup for sub-directories or path based
 * URLs for subsites.
 * 
 * DO NOT EDIT UNLESS YOU KNOW WHAT YOU ARE DOING!
 */

use Grav\Common\Filesystem\Folder;

// Get relative path from Grav root.
$path = isset($_SERVER['PATH_INFO'])
   ? $_SERVER['PATH_INFO']
   : Folder::getRelativePath($_SERVER['REQUEST_URI'], ROOT_DIR);

// Extract name of subsite from path
$name = Folder::shift($path);
$folder = "sites/{$name}";
$prefix = "/{$name}";

if (!$name || !is_dir(ROOT_DIR . "user/{$folder}")) {
    return [];
}

// Prefix all pages with the name of the subsite
$container['pages']->base($prefix);

return [
    'environment' => $name,
    'streams' => [
        'schemes' => [
            'user' => [
               'type' => 'ReadOnlyStream',
               'prefixes' => [
                   '' => ["user/{$folder}"],
               ]
            ]
        ]
    ]
];

Any ideas what I could be doing wrong? Thanks for the help!

I have similar setup and I cannot see anything wrong in yours.

First thing I would check if setup.php gets called and returns the proper array.