// Serial is the serial monitor
// Serial1 is the GPS data

int intChar;
char charChar;
intChar = Serial1.read();
if(inChar != -1){
charChar = (char)intChar;
Serial.print(charChar);
}

I have been using the M5Stack GPS v1.1 and it was set to 115200@7N1, not the advertised 115200@8N1 so might be an issue there (I got gibberish at first)

Finally my M5Stack GPSv1.1 works fine with an Adafruit Itsy Bitsy 3v controller and an ESP32S3 based controller but not with the Seeed Wio Terminal. With the Seeed Wio Terminal I get nothing at all - no gibberish, absolutely nothing. It's as if the signal is not there (but it is !!).

#include <M5Core2.h>
#include <TinyGPS++.h>

TinyGPSPlus gps;
HardwareSerial GPSRaw(2);

void setup() {
  M5.begin();
  M5.Lcd.setTextSize(2);
  M5.Lcd.setTextColor(TFT_YELLOW);
  M5.Lcd.println("Test GPS v2.1 - Core2");
  M5.Lcd.setTextColor(TFT_WHITE);
  M5.Lcd.println("Waiting satellites...");

  GPSRaw.begin(9600, SERIAL_8N1, 13, 14);
}

void loop() {
  M5.update();
  
  while (GPSRaw.available() > 0) {
    gps.encode(GPSRaw.read());
  }

  if (gps.location.isUpdated()) {
    M5.Lcd.fillRect(0, 60, 320, 180, BLACK); 
    M5.Lcd.setCursor(0, 60);
    
    M5.Lcd.setTextColor(TFT_GREEN);
    M5.Lcd.printf("Connected satellites: %d\n\n", gps.satellites.value());
    
    M5.Lcd.setTextColor(TFT_WHITE);
    M5.Lcd.printf("LAT: %.6f\n", gps.location.lat());
    M5.Lcd.printf("LNG: %.6f\n", gps.location.lng());
    M5.Lcd.printf("HGH: %.1f meters\n\n", gps.altitude.meters());
    
    // UTC hour sync with satell
    if (gps.time.isValid()) {
      M5.Lcd.setTextColor(TFT_CYAN);
      M5.Lcd.printf("UTC hour: %02d:%02d:%02d\n", gps.time.hour(), gps.time.minute(), gps.time.second());
    }
  }
}```