На одной форме кнопка работает, а на другой - нет

unit Unit1;
interface
uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, Buttons, Mask, ExtCtrls, Spin, ComCtrls, ScktComp, Menus, Comm32;
 type
  TDataByte = array of word;
type
  TForm1 = class(TForm)
    ComboBox1: TComboBox;
    ComboBox2: TComboBox;
    SpeedButton1: TSpeedButton;
//***
    MainMenu1: TMainMenu;
    N1: TMenuItem;
    N2: TMenuItem;
    procedure SpeedButton1Click(Sender: TObject);
   
  private
    { Private declarations }
  public
    { Public declarations }
    com: TComm32;
    procedure comReceiveData(Sender: TObject; Buffer: Pointer;
      BufferLength: Word);
    procedure packet(Str: String);
  end;
var
  Form1: TForm1; 
 implementation
uses CommUnit;
{$R *.dfm}
//******КНОПКА******
procedure TForm1.SpeedButton1Click(Sender: TObject);
begin
 com.BaudRate:= StrToint(ComboBox2.Text);
 com.CommPort:= ComboBox1.Text;
end;

Form2:=TForm2.Create(Owner);
Form2.ShowModal;
Form2.Free;

unit CommUnit;
interface
uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, ExtCtrls, Buttons;
type
  TForm2 = class(TForm)
    GroupBox1: TGroupBox;
    ComboBox1: TComboBox;
    ComboBox2: TComboBox;
    Label1: TLabel;
    Label2: TLabel;
    Button1: TButton;
    Shape1: TShape;
    SpeedButton1: TSpeedButton;
    procedure Button1Click(Sender: TObject);
    procedure SpeedButton1Click(Sender: TObject);
  private
    { Private declarations }
  public
 
    { Public declarations }
  end;
var
  Form2: TForm2;
implementation
uses Unit1;
{$R *.dfm}
//****КНОПКА НА НОВОЙ ФОРМЕ**********
procedure TForm2.Button1Click(Sender: TObject);
begin
Form1.com.BaudRate:= StrToint(ComboBox2.Text);
Form1.com.CommPort:= ComboBox1.Text;
end;