Take note of the changes below;
Private Sub CommandButton1_Click()

    Dim rngFilter As Range
    
    With Sheets("S04FLXLS")
            .AutoFilterMode = False
        Set rngFilter = .Range("B1:B" & .Rows.Count).End(xlUp)
    End With
    
    With rngFilter
        .AutoFilter Field:=2, Criteria1:=TextBox1.Value & "*"
        .Range("A1:N" & .Rows.Count).End(xlUp).SpecialCells(12).Copy Destination:=Sheet2.Range("A1")
        .AutoFilter
    End With

End Sub