It seems like the Yaw values seem to always be drifting – is this a known issue, or is there a way to account for it?

My code:

#include <M5StickC.h>

float accX = 0.0F;
float accY = 0.0F;
float accZ = 0.0F;

float gyroX = 0.0F;
float gyroY = 0.0F;
float gyroZ = 0.0F;

float pitch = 0.0F;
float roll  = 0.0F;
float yaw   = 0.0F;

void setup() {
  // put your setup code here, to run once:
  M5.begin();
  M5.IMU.Init();
  M5.Lcd.setRotation(1);
  M5.Lcd.fillScreen(BLACK);
  M5.Lcd.setTextSize(1);
  M5.Lcd.setCursor(40, 0);
  M5.Lcd.println("IMU TEST");
  M5.Lcd.setCursor(0, 10);
  M5.Lcd.println("  X       Y       Z");
  M5.Lcd.setCursor(0, 50);
  M5.Lcd.println("  Pitch   Roll    Yaw");

  Serial.begin(9600);
}

float temp = 0;
/*****************************************
M5.IMU.getGyroData(&gyroX,&gyroY,&gyroZ);
M5.IMU.getAccelData(&accX,&accY,&accZ);
M5.IMU.getAhrsData(&pitch,&roll,&yaw);
M5.IMU.getTempData(&temp);
*****************************************/
void loop() {
  // put your main code here, to run repeatedly:
  M5.IMU.getGyroData(&gyroX,&gyroY,&gyroZ);
  M5.IMU.getAccelData(&accX,&accY,&accZ);
  M5.IMU.getAhrsData(&pitch,&roll,&yaw);
  M5.IMU.getTempData(&temp);
  
  M5.Lcd.setCursor(0, 20);
  M5.Lcd.printf("%6.2f  %6.2f  %6.2f      ", gyroX, gyroY, gyroZ);
  M5.Lcd.setCursor(140, 20);
  M5.Lcd.print("o/s");
  M5.Lcd.setCursor(0, 30);
  M5.Lcd.printf(" %5.2f   %5.2f   %5.2f   ", accX, accY, accZ);
  M5.Lcd.setCursor(140, 30);
  M5.Lcd.print("G");
  M5.Lcd.setCursor(0, 60);
  M5.Lcd.printf(" %5.2f   %5.2f   %5.2f   ", pitch, roll, yaw);

  M5.Lcd.setCursor(0, 70);
  M5.Lcd.printf("Temperature : %.2f C", temp);

  // Plotting
  Serial.print("pitch:");
  Serial.print(pitch);
  Serial.print(",");
  Serial.print("roll:");
  Serial.print(roll);
  Serial.print(",");
  Serial.print("yaw:");
  Serial.println(yaw);
  
  delay(100);
}

Full documentation on the various IMU readings when the device is in different orientations here: https://www.notion.so/scientiffic/M5Stick-IMU-Calibration-dbb5e3fa4d35444da7ca7decb418ed20