Excel: Range.Cut() or Range.ClearContents() changes the ActiveWorkBook

I have created an application that does following things:

1. Open workbook from path using Excel.Interop

    newwb = ExcelApp.Workbooks.Open(path,
                                        0,
                                        false,
                                        Type.Missing,
                                        Type.Missing,
                                        Type.Missing,
                                        true,
                                        Type.Missing,
                                        Type.Missing,
                                        true,
                                        false,
                                        Type.Missing,
                                        false,
                                        Type.Missing,
                                        Type.Missing);
    newwb.Activate();
   

2. Set ScreenUpdating to false so that the user will not be aware of the active workbook.

3. Performing some operations like Range.Cut() or Range.ClearContents() changes the active workbook back to "Book1"

I can set the active workbook back to newwb but that would be a performance overhead and I would like to know the exact reason that changes active workbook (But it doesn't trigger workbook changed event as well).

Any help or suggestion would be great.

Thanks.