PWA show multiple Forms WebGridpanel Error

I Start a Pwa with a Main Form and two different sideForms.
With

Procedure TForm1.StartForm2NJF();
var
Form2: TForm2;

procedure AfterCreate(AForm:TObject);
begin
(AForm as TForm2).doSomething;
end;

procedure AfterShowModal(AValue: TModalResult);
begin
startForm3();
end;
begin
Form2:=TForm2.CreateNew(@AfterCreate);
Form2.ShowModal(@AfterShowModal);
end;

I get
"ERROR Duplicate Component name: "WebGridPanel1" | fMEssage::Duplicate component name: "WebGridPanel1" FJSE::Error: duplicate component name: "WebGridPanel1" fHelpContext::0 at http://localhost:8000....."

I Changed the WebGridPanel names on al Forms, so i definitely have just 1 WebgridPanel1 in the Main Form.
Error still occurs.

Dirty Workaround:
procedure AfterShowModal(AValue: TModalResult);
begin
showmessage('random');
startForm3();
showmessage('random');
end;

What is startForm3() doing?
Did you try to use the approach with await() as shown in the demo under Demo\Basics\MultiForm?

startForm3 is more or less the same procedure as start Form2.

Procedure TForm1.StartForm3();
var
Form3: TForm3;

procedure AfterCreate(AForm:TObject);
begin
(AForm as TForm3).cbTask.Items.Add('Task1');
(AForm as TForm3).cbTask.Items.Add('Task2');
(AForm as TForm3).cbTask.Items.Add('Task3');
end;

procedure AfterShowModal(AValue: TModalResult);
begin
Abgabe();
WebLabel1.Caption:='Fertig, Bitte App Beenden';
end;
begin
Form3:=TForm3.CreateNew(@AfterCreate);
Form3.ShowModal(@AfterShowModal);
end;

Uptill now, i orientated on:
your Video

But it seems its a bit old. ;)
i will try the await approach.
i was more bewildered that the workaround with the two showmessages worked and thought maybe theres some weird thing happening you might be interested in.

await works great. Thx