Yaw value of 200 when roll and pitch are fine using madgwick filter arduino

Question

my yaw value seems to be offset right from the start and all values seem to be extremely slow to respond to any movement - before using the filter each sensors values responded adequately.

I have tried alternating the axes of the magnetometer with no luck. I am quite new to coding and to microcontrollers so i am not too knowledgeable. I wanted to get a working euler angle programme before going onto use quaternions to log flight data for my model rocket.

 `#include "Arduino_BMI270_BMM150.h"
 #include <MadgwickAHRS.h>

float gx, gy, gz, ax, ay, az, mx, my, mz;
float roll, pitch, yaw;
Madgwick filter;

unsigned long lastMagUpdate = 0; //can hold large positive integers 
const int magUpdateRate = 100; // Magnetometer update rate in milliseconds (10 Hz)

void setup() {
 // Existing setup code...
Serial.begin(9600);
while (!Serial) 
Serial.println("Started");

 if (!IMU.begin()) {
  Serial.println("IMU initialization unsuccessful");
  while (1);
 }
  Serial.print("Accelerometer sample rate = ");
  Serial.print(IMU.accelerationSampleRate());
  Serial.println(" Hz");

  Serial.print("Gyroscope sample rate = ");
  Serial.println(IMU.gyroscopeSampleRate());
  Serial.println(" Hz");

  Serial.println("Magnetometer sample rate = ");
  Serial.print(IMU.magneticFieldSampleRate());
  Serial.println(" Hz");

  filter.begin(IMU.accelerationSampleRate());
  }

  void loop() {
    if (IMU.gyroscopeAvailable() && IMU.accelerationAvailable()) {
      float Rgx, Rgy, Rgz;
      float Rax, Ray, Raz;
      IMU.readGyroscope(Rgx, Rgy, Rgz);
      IMU.readAcceleration(Rax, Ray, Raz);

      convertToRadians(Rgx,Rgy,Rgz); 
      convertToM_s2(Rax,Ray,Raz);




     // Update the magnetometer readings less frequently
   if (millis() - lastMagUpdate >= magUpdateRate) {    //millis returns time since program began
  if (IMU.magneticFieldAvailable()) {            
    lastMagUpdate = millis();
  }
    }


filter.update(gx, gy, gz, ax, ay, az, mx, my, mz);

// Convert to Euler angles
roll = filter.getRoll();
pitch = filter.getPitch();
yaw = filter.getYaw();

// Output the data
Serial.print("Roll: "); Serial.print(roll); Serial.print("\t");
Serial.print("Pitch: "); Serial.print(pitch);        Serial.print("\t");
  Serial.print("Yaw: "); Serial.print(yaw);          Serial.println();
    }
    }
     void convertToRadians(float Rgx, float Rgy, float Rgz) {
     gx = Rgx*PI/180; gy= Rgy*PI/180; gz = Rgz*PI/180;
    }
   void convertToM_s2(float Rax, float Ray, float Raz) {
    ax =Rax*9.81; ay=Ray*9.81; az =Raz*9.81;
   }
 `