wpdb get_results() returns only 2 rows

I am trying to create custom admin widget to present how many users has registered within last days. I have created function as below:

function mdbootstrap_add_dashboard_recent_users(){ 
global $wpdb;

$query = "
    SELECT count(*) as counter, DATE(wp_users.user_registered) as regdate
    FROM wp_users 
    GROUP BY DATE(wp_users.user_registered) 
    ORDER BY DATE(wp_users.user_registered) desc";

$posts = $wpdb->get_results($query,OBJECT);
print_r( $posts);
 }

However for some reason it’s returning only 2 rows:

Array ( [0] => stdClass Object ( [counter] => 1 [regdate] => 2016-01-12 ) [1] => stdClass Object ( [counter] => 3 [regdate] => 2016-01-04 ) )

Which BTW shows wrong values, as the same query run from PHP MyAdmin gives result as follow:

• counter regdate
• 16 2016-01-13
• 37 2016-01-12
• 51 2016-01-11
• 25 2016-01-10
• 21 2016-01-09
• 26 2016-01-08
• 24 2016-01-07
• 24 2016-01-06
• 18 2016-01-05
• 20 2016-01-04
• 5 2016-01-03

I was looking for similar issue however most of the topics covers issue with only 1 row when people use get_row instead of get_results. I have played with different parameters like ARRAY_N, OBJECT, ARRAY_A but didn’t work – query always returns 2 rows.