Sending char string from matlab to arduino using serial com

Hi i am trying to simply send the character string '<180>' to arduino from matlab using serial communication in order to light a led. for some reason arduino isnt receiving the correct data. if i type <180> into the serial monitor on the arduino software the led lights up. any help is appreciated.

matlab code:

%% Serial communication with Arduino

x = serial('COM4','BAUD',9600);
fopen(x);
             
% a= input('Press 1 to turn ON LED & 0 to turn OFF:');
a = '<180>';
fprintf(x,'%s',a);  
pause(4)
fclose(x);

Arduino code:

const byte numChars = 32;
char receivedChars[numChars];

boolean newData = false;

void setup() {
    Serial.begin(9600);
    Serial.println("<Arduino is ready>");
    pinMode(13, OUTPUT);
}

void loop() {
    recvWithStartEndMarkers();
    showNewData();
}

void recvWithStartEndMarkers() {
    static boolean recvInProgress = false;
    static byte ndx = 0;
    char startMarker = '<';
    char endMarker = '>';
    char rc;
 
    while (Serial.available() > 0 && newData == false) {
        rc = Serial.read();

        if (recvInProgress == true) {
            if (rc != endMarker) {
                receivedChars[ndx] = rc;
                ndx++;
                if (ndx >= numChars) {
                    ndx = numChars - 1;
                }
            }
            else {
                receivedChars[ndx] = '\0'; // terminate the string
                recvInProgress = false;
                ndx = 0;
                newData = true;
            }
        }

        else if (rc == startMarker) {
            recvInProgress = true;
        }
    }
}

void showNewData() {
    if (newData == true) {
        Serial.print("This just in ... ");
        Serial.println(receivedChars);
long number = atol(receivedChars); 
    if (number == 180){
        digitalWrite(13, HIGH);
        
      }
      else {
        digitalWrite(13, LOW);
      }
        newData = false;
    }
}