Delphi 10.3 Multiple MDI Forms

Question

got here a two Forms which are both set to fsMDIForm . And two Child Forms fsMDIChild.

When I run the Application it looks like both Parent Forms are correctly created because I can see the Space where the Child Forms would show up.

But for some reason the the Second MDIForm which is created from the Main MDI Form the Children are not being displayed, instead they are created on the Main MDI Form .

This is how the Second MDI Form is created

procedure TMain.menChefReportClick(Sender: TObject);
begin
  Timer1.Enabled:=false;
  CloseAllMDIChildren;

  Application.CreateForm(TChefReport, ChefReport);
  ChefReport.PopupParent:=Main;
  ChefReport.ShowModal;
  ChefReport.Free;
  ChefReport:=nil;

  OpenAllMDIChildren;
  Timer1.Enabled:=true;
end;

This closes all MDI Children for the Main Form , I am doing this because I am displaying Live data which is not required as long as I am in the Second MDI Form.

On the Second MDI form I am trying to create the Children like this :

procedure TChefReport.OpenAllMDIChildren;
var AQuery : TADOQuery;
    Y : integer;
begin
  AQuery := TADOQuery.Create(nil);
  try
    AQuery.Connection:=dmConnection.XLR;
    AQuery.LockType:=ltReadOnly;
    AQuery.SQL.Clear;
    AQuery.SQL.Add('select Line from LINE_SETTINGS order by line');
    AQuery.Open;

    AQuery.DisableControls;

    Y:=0;

    while not AQuery.Eof do
    begin
      Application.CreateForm(TChefReportLine,ChefReportLine);

      ChefReportLine.Caption:='Linie Nr. '+AQuery.FieldByName('Line').AsString;
      ChefReportLine.FLine:=AQuery.FieldByName('Line').AsInteger;

      ChefReportLine.Top:=0;
      ChefReportLine.Left:=0;

      Y:=Y+ChefReportLine.Height;


      AQuery.Next;
    end;

  finally
    AQuery.Free;
  end;
end;

It does create them . But unfortunately on the Main MDI Form .

Is it possible and how do I create them on the Second MDI Form ( ChefReport ) ?

Thank you!

UPDATE

Solutions was here : Allow multiple MDI Parent Forms on same Application

And I create the Children Like this :

procedure TChefReport.OpenAllMDIChildren;
var AQuery : TADOQuery;
    Y : integer;

    ChefReportLine : TChefReportLine;
begin
  AQuery := TADOQuery.Create(nil);
  try
    AQuery.Connection:=dmConnection.XLR;
    AQuery.LockType:=ltReadOnly;
    AQuery.SQL.Clear;
    AQuery.SQL.Add('select Line from LINE_SETTINGS order by line');
    AQuery.Open;

    AQuery.DisableControls;

    Y:=0;

    while not AQuery.Eof do
    begin
      ChefReportLine := TChefReportLine.Create(ChefReport);

      ChefReportLine.Caption:='Linie Nr. '+AQuery.FieldByName('Line').AsString;
      ChefReportLine.FLine:=AQuery.FieldByName('Line').AsInteger;

      ChefReportLine.Top:=Y;
      ChefReportLine.Left:=0;

      Y:=Y+ChefReportLine.Height;


      AQuery.Next;
    end;

  finally
    AQuery.Free;
  end;
end;