Excel sheet opening on OLEDBCommand query

Question

I have an issue that is very similar to a question already posted here but not resolved. This issue is that when my app reads from an excel file (can happen with a CSV too) with oledb and the file is already opened in Excel (not through the app, the user just has it opened separately) a new Excel will open the file in read-only mode. If the file isn't opened at all, no Excel comes up. It happens right when the connection is opened - conn.Open()

Here is a method for reference:

public static DataTable GetDataTableFromExcelSheet(string ExcelFilePath, string SheetName)
        {
            string connectionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + ExcelFilePath + ";Extended Properties=\"Excel 12.0;HDR=Yes;IMEX=1\""; 
            string query = "SELECT * from [" + SheetName + "$]";
            System.Data.DataTable dt = new System.Data.DataTable();
            using (OleDbConnection conn = new OleDbConnection(connectionString))
            {
                conn.Open();
                using (OleDbDataAdapter dataAdapter = new OleDbDataAdapter(query, conn))
                {
                    dataAdapter.Fill(dt);
                }
                conn.Close();

            }
            return dt;
        }

Is there a way I can prevent Excel opening? Or at least not make it visible? (the app doesn't try to run the Excel app anywhere, the class doesn't even have interop)