I'm still learning linq, now i'm getting confused. I need data for report from 3 tables, I get the result, but it's duplicate. I have used distinct but it's not working, n I need data to be sum still not working.

Here is my query, can somebody explain what's wrong?

var report= (from u in myDb.TBL_TRANSAKSI_MKN_MNMs.AsEnumerable()
  where u.TGL_TRANSAKSI.Value.Date.Equals(dateTimePicker1.Value.Date)
  join l in myDb.TBL_DETAIL_TRANSAKSIs.AsEnumerable() on u.ID_NOTA equals l.ID_NOTA
  join m in myDb.TBL_MKN_MNMs.AsEnumerable() on l.ID_MKN_MNM equals m.ID_MKN_MNM
  group new { u, l, m } by new { m.NAMA_MKN_MNM, m.HARGA_JUAL, u.TGL_TRANSAKSI, l.ID_MKN_MNM, u.USERNAME, l.Jumlah }
  into grp                 
  select new 
  {                         
      MakanMinum = grp.Key.NAMA_MKN_MNM,
      HargaJual = grp.Key.HARGA_JUAL,
      Stok = grp.Sum(groupedthing => groupedthing.l.Jumlah), 
      Tanggal =  grp.Key.TGL_TRANSAKSI,
      Jumlah =(grp.Key.HARGA_JUAL * grp.Sum(groupedthing => groupedthing.l.Jumlah)),
      Total = grp.Sum(grouptotal => grp.Key.HARGA_JUAL * grp.Sum(groupedthing => groupedthing.l.Jumlah)),
      Username = grp.Key.USERNAME
  }).Distinct();