Problem with Arduino_Apollo3 Core

[wivach]

Enviroment : Window Windows 11 Education Version 22H2
Arduino IDE 1.8.19
Arduino_Apollo3 Core Version 2.2.1
Board : SparkFun Artemis Module

1. With this code :
   UART SerialCOM(1, 40, 39); // pin 40 as rx pin 39 as tx
   void setup()
   {
   SerialCOM.begin(9600,SERIAL_8N1);
   Serial.begin(9600);

        Serial.println("Starting USBSerial");
        SerialCOM.println("Starting SerialCOM");
      }
      void loop() {
      
        if (Serial.available()>0) 
        {      
          SerialCOM.write(Serial.read()); 
        }
      
        if (SerialCOM.available()>0) 
        {
          Serial.write(SerialCOM.read());
        }
      }
   

Even the signal cables between pins 39 and 40 are not connected together. Why does Serial Mornitor on the computer get the message "Starting SerialCOM" and when typing any message on Serial Mornitor will get a reply message even though there is no connection. Connect the legs, legs 39 and 40 together.
2. Why can't different baud rates be used between UART0 and UART1, for example UART0 baud rate 115200 and UART1 baud rate 9600?
3. 'Serial1' was not declared in this scope.
4. In some cases such as Replacing the signal pin UART SerialCOM(1, 40, 39); to UART SerialCOM(1, 39, 40); IDE can compile and program a microcontroller. But the microcontroller will not work. without notification of error. and even reprogramming the code back to the previous code that works UART SerialCOM(1, 39, 40); to UART SerialCOM(1, 40, 39 ); and reprogram The microcontroller will not work. until having to close-open the IDE again and the program again to be able to use it again
Thank You.