BCTrackbarUpdown control bug

[qwer0123456]

BCTrackbarUpdown1Change execute bug

procedure TForm1.BCTrackbarUpdown1Change(Sender: TObject; AByUser: boolean);
begin
showmessage('1');
end;

process run execute -> messagebox call

The trackbar didn't move change

When the program is executed, it is executed unconditionally once

Isn't this a bug?

######## add in fo ########

BCTrackbarUpdown1.value = 0 -> process execute -> BCTrackbarUpdown1Change call

BCTrackbarUpdown1.value = 50 -> process execute -> BCTrackbarUpdown1Change no function call

what value 0 build -> execute change call

[qwer0123456]

Why is the initial value 50?

Isn't it more normal to have an initial code value of 0?

this is weird