no refreshing FMX Controls

Question

I have simple fmx form(Delphi 10.2 Tokyo):

in code I show Button2 for second:

procedure TForm6.FormCreate(Sender: TObject);
begin
    Button2.Visible :=false;
end;

procedure TForm6.Button1Click(Sender: TObject);
begin
    Button2.Visible := true;
    TTask.Create(procedure
        begin
            Sleep(1000);
            TThread.Synchronize(nil, procedure
                begin
                    Button2.Visible := false;
                    //tries
                    //Button2.Repaint;
                    //Layout1.Repaint;
                    //Self.InvalidateRect(Self.Bounds);
                    //Application.ProcessMessages;
                end);
        end).Start;
end;

but after button2 hides, artefact appears. Its gone after manually form resize.

How to force it to refresh?

Answer 1

You need to use

ShadowEfect1.UpdateParentEffects;