Working with go-ora refcursor, sometimes I’m getting can't query RefCursor: driver: bad connection

I use shared connectin like:

func main() {
    // Establish a connection to the Oracle database
    dsn := "oracle://username:password@hostname:port/service_name"
    db, err := sql.Open("oracle", dsn)
    if err != nil {
        log.Fatalf("Failed to connect to the database: %v", err)
    }
    defer db.Close()  // Ensure the database connection pool is closed when main exits

    // Reuse the same connection pool to call a stored procedure with REF CURSOR
    for i := 0; i < 5; i++ {
        if err := callStoredProcedure(db); err != nil {
            log.Printf("Failed to call stored procedure: %v", err)
        }
    }
}

func callStoredProcedure(db *sql.DB) error {
    // Create a variable to hold the REF CURSOR (sql.Rows)
    var refCursor *sql.Rows

    // Execute the stored procedure
    stmt, err := db.Prepare(query)
    if err != nil {
        return fmt.Errorf("failed to prepare statement: %w", err)
    }
    defer stmt.Close()  // Ensure the statement is closed after execution

    // Execute the statement and obtain the REF CURSOR
    _, err = stmt.Exec(&refCursor)
    if err != nil {
        return fmt.Errorf("failed to execute statement: %w", err)
    }
    defer refCursor.Close()  // Ensure the REF CURSOR is closed after processing

    // Process the rows returned by the REF CURSOR
    for refCursor.Next() {
    }

    return nil
}

I wonder is it ok to reuse the same db, err := sql.Open(“oracle”, dsn), shoud I create it for every request maybe since I use refcursor?