mbed MPU6050 - Using the Madgwick Orientation Filter library

Question

I am currently trying to add a madgwick filter for MPU6050 in Mbed Studio OS6. I picked out a library to make implementation easier: https://os.mbed.com/users/hudakz/code/MPU6050/

I've tried to follow the library as best I can but the Madgwick filter setup isn't working as I had hoped. The time and temperature are showing correctly but the orientation values are listed as "0.00":

TIME, PITCH, ROLL, YAW, TEMP

00:11:59:716, 0.00, 0.00, 0.00, 25.48

Now here is the loop, what am I missing in order to get values in my output?

// Loop
while(1)
{
    if (mpu6050.dataReady()) {
        mpu6050.accel(); // Read 2g acceleration data
        mpu6050.gyro(); // Read 250° gyroscope data
        //mpu6050.setGain(float beta, float zeta); // Do I need this?
        mpu6050.madgwickFilter(0.005f); // 5ms = 200Hz

        // Using existing functions defined in the .cpp and .h files
        float pitch = mpu6050.pitch();
        float roll = mpu6050.roll();
        float yaw = mpu6050.yaw();

        // Read temperature - this works
        float temperature = mpu6050.temp();
        // Read time - this works
        auto elapsed_time = t.elapsed_time();

        // Print values to serial console - Now includes Time
        snprintf(buffer, sizeof(buffer), 
             
             // Seperated by comma for data collection and visualiser
            "%02d:%02d:%02d:%03d, %.2f, %.2f, %.2f, %.2f\n",
            int (elapsed_time / 1h), int((elapsed_time % 1h) / 1min), int((elapsed_time % 1min) / 1s), int((elapsed_time % 1s) / 1ms),
            pitch, roll, yaw, temperature);
            
            // Raw values:
            //"[%02d:%02d:%02d,%03d] Accel: (X: %.2f, Y: %.2f, Z: %.2f) G | Gyro: (A: %.2f, B: %.2f, C: %.2f) °/s | Temperature: %.2f°C\n\r", 
            //int (elapsed_time / 1h), int(elapsed_time % 1h / 1min), int(elapsed_time % 1min / 1s), int(elapsed_time % 1s / 1ms),
            //ax, ay, az, gx, gy, gz, temperature);

        printf("%s", buffer);

        ThisThread::sleep_for(100ms); // Delay to read data
    }
}