ADO.Net executenonquery run return -1

when i implemented an update Functionality using asp.net.

I got a very strange return -1 in each execution. since I had a conditional check to verify each update.

As I know that sqlComm.ExecuteNonQuery() return the number of rows being affected by the Update, Insert operation.

when i went back to look at my Stored-Procedure i found that SET NOCOUNT ON; in my Stored Procedure.

Alter PROCEDURE [dbo].[Customer_Data_Master_Upd]
@Prospect nvarchar(10)
AS
BEGIN 
     SET NOCOUNT ON;
  
    Update Customer_Data_Master
    Set Status='N'
    where LCDGCC =@Prospect

END

after I commented out the line Set NOCOUNT ON

My conditional check works as plan. In My opinion, the Set NOCOUNT On should only be enable in Select statment to improve performance.