Dental plan results affected by Mongo query syntax

gistfile1.txt

  # Snippet illustrates a query on hbx_enrollemnts 
  
  
  # FINDS familes including ones that have ivl dental and employer_sponsored health
  families = Family.where(:"households.hbx_enrollments.kind" => "employer_sponsored", :"households.hbx_enrollments.coverage_kind" => 'dental')
  puts families.size  #36
  
  # FINDS families where the enrollment has coverage_kind='dental' and kind: 'employer_sponsored' 
  families=Family.where(:'households.hbx_enrollments' => 
    {
      "$elemMatch" => {
         kind: 'employer_sponsored',
         coverage_kind: 'dental'
      }
  })
  puts families.size # 0