RAK4631 with RAK19010 UART not working

I developed an application with Arduino BSP that uses the RAK4631 core module with a RAK5005-O base board. The application makes use of UART1 (available on the J10 header of the base board).

However, when I move the RAK4631 to a RAK19010 base board, UART1 seems to be not working.
To test the UART I wrote a simple test application (see sample code below) that echo everything received on UART1 to the Bluetooth UART Tool on Android, and vice versa anything received on the BLE UART to UART1. However, I cannot get UART1 to send or receive anything.

#include <Arduino.h>
#include <LoRaWan-RAK4630.h> //http://librarymanager/All#SX126x
#include <bluefruit.h>
#include <Wire.h>

BLEUart g_bleUart;
BLEDfu g_bleDfu;
bool g_bleUartConnected = false;

void setup_ble();

void setup() 
{
  time_t timeout = millis();
  Serial1.begin(115200);
  while (!Serial1)
  {
      if ((millis() - timeout) < 5000)
          delay(300);
      else
          break;
  }

  // Setup BLE
  setup_ble();
}

void loop() 
{
  if (Serial1.available())
  {
      String text = Serial1.readStringUntil('\n');
      if (g_bleUartConnected)
      {
          g_bleUart.printf(text.c_str());
          delay(50);
      }
  }

  if (g_bleUartConnected)
  {
    if (g_bleUart.available())
    {
      String text = g_bleUart.readStringUntil('\n');
      Serial1.println(text.c_str());
    }
  }

  delay(10);
}

Also, after some investigation I found that the RAK19010 base board mentions UART0 on the J10 header (see image below).

image

The documentation for the J10 header, however, make mention of UART 1. I assume that the J10 should be UART1, is this correct?

Any help on this would be appreciated.

Thanks

Welcome to the forum @christolinde

It is confusing, but

RX1/TX1 ==> Serial1
RX0/TX0 ==> Serial2

And the pins on the header are different between RAK5005-0 and the RAK19010.