GROUP_CONCAT() in my Laravel built query gives incorrect values

I have 3 tables: Users, Properties, Units
User table:

user_id   user_name

Properties table

pty_id   pty_name   user   pty_status

Units Table

unit_id   unit_name  pty_id  unit_status

I want to show user details, number of properties and units and their details. Here is my query:

DB::statement('SET SESSION group_concat_max_len = 10485760');

$ar = DB::table('users as u')
    ->leftjoin('properties as p', function($join)  {
        $join->on('p.user_id', '=', 'u.user_id')->where('p.pty_status', '!=' ,0 ); 
    })       
    ->leftJoin(
        DB::raw("
            (select COALESCE(count(unit_id),0) AS cntunits, pty_id as temp_pty
            from  property_units as pu3 
            left join properties as p2 on pu3.unit_pty_id = p2.pty_id
            where pu3.unit_status!=0  
            group by p2.pty_id
            ) as temp
        "),
        'p.pty_id',
        '=',
        'temp.temp_pty'
    )
    ->select(
        DB::raw("group_concat(DISTINCT CONCAT(ej_p.pty_id,'|',ej_p.pty_name,'|',cntunits)) as pty_details"), 
        DB::raw("group_concat(DISTINCT CONCAT(ej_p.pty_id,'|',ej_p.pty_name)) as pty_details_copy")
    )
    ->paginate(10);

When I GROUP_CONCAT() the unit_count, only those properties and units are concatenated where unit exists.

For example the above query returns the following result:

 pty_details              pty_details_copy
  7|I2|2       7|I2, 22|tR ,51|SG APARTMENT,54_||_GA APARTMENTS,

Why properties with units (where unit count=0) are not binding? Where have I gone wrong?

EDIT

Here is the raw query:

select group_concat(DISTINCT CONCAT(p.pty_id,'|',p.pty_name,'|',cntunits)) as pty_details, 
    group_concat(DISTINCT CONCAT(p.pty_id,'|',p.pty_name)) as pty_details_copy
from users as  u
left join properties as p on p.user_id = u.user_id and p.pty_status !=0
left join 
    (select COALESCE(count(unit_id),0) AS cntunits, pty_id as temp_pty
     from  property_units as pu3 
     left join properties as p2 on pu3.unit_pty_id = p2.pty_id
     where pu3.unit_status!=0  
     group by p2.pty_id) as temp on p.pty_id = temp.temp_pty

As Solarflare suggested, i got the required result when I changed the query like this:

  $ar = DB::table('users as u')
     ->leftjoin('properties as p', function($join)  {
               $join->on('p.user_id', '=', 'u.user_id')->where('p.pty_status', '!=' ,0 ); 
              })

     ->leftJoin(
             DB::raw("
              (select COALESCE(count(unit_id),0) AS cntunits, pty_id as temp_pty
              from  property_units as pu3 
              left join properties as p2 on pu3.unit_pty_id = p2.pty_id
              where pu3.unit_status!=0  
              group by p2.pty_id) as temp"), 'p.pty_id', '=', 'temp.temp_pty')

      ->select(
  DB::raw("group_concat(DISTINCT CONCAT(ej_p.pty_id,'|',ej_p.pty_name,'|',coalesce(cntunits, 0))) as pty_details"))->paginate(10);