Voyager admin menu isn't shown for user with role "admin" with all permissions

I've created new user by regular "Register" link at app frontend, then issued

php artisan voyager:admin this_user@mail.com

and logged in to Voyager with this user's login and password. What I saw is empty space in the panel on the left instead of admin menu:

I've checked roles and permissions in database. In users table this user has role_id set to 1, which is "admin" in table roles and has all permissions in permission_role. This seems to be OK.

Why this user doesn't see the admin menu?

via Chebli Mohamed