TMSFNCPlanner add Items is very slow. (Android Platform und IOS)

first 100 112ms, next 100 689ms, next 100 1804ms, next 100, 3446ms

procedure TForm1.Button1Click(Sender: TObject);
var
i : integer;
s : TStopWatch;
begin
s := TStopWatch.Create;
s.Start;
plWoche.Items.BeginUpdate;
for i := 1 to 100 do begin
with plWoche.Items.Add do begin
Text := i.ToString;
end;
end;

plWoche.Items.EndUpdate;
s.Stop;
showMessage(s.ElapsedMilliseconds.ToString+' ms');
end;

Please use

plWoche.BeginUpdate;

plWoche.EndUpdate;

thank you for your quick response. i use the Items.BeginUpdate because i know this from the VCL Planner.