Core becomes unresponsive after Http request [Solved]

Firmware
14

Thanks @bko and @Hootie81 for your help

So if I understood correctly after making a http request I will have to wait for a while till there is some response then read everything from the TI WiFi chip buffer using and flushing it by

while (client.available()) client.read(); 
client.flush();

Then again wait for a while till the request is complete and then call client.stop().

So if my understanding is correct please let me know if my below code implementation is correct

void pushNotify(const char* title,const char* msg){
    Serial.print("inside pushNotify methode..\r\n");
    char line[255];
    char response[512];
    int pos=0;
    
    Serial.print("connected to ");
    Serial.println(HOSTNAME);
    
    client.connect(HOSTNAME,80);
    sprintf(line, "POST %s HTTP/1.1\r\n", PATHNAME);
    client.write( (const uint8_t*)line, strlen(line) );
    client.write( (const uint8_t*)"Connection: close\r\n", strlen("Connection: close\r\n") );
    
    sprintf(line, "Host: %s:%d\r\n", HOSTNAME, 80);
    client.write( (const uint8_t*)line, strlen(line) );
    
    sprintf(line, "Content-Length: %d\r\n", strlen(title) + strlen(msg)  + 12);
    client.write( (const uint8_t*)line, strlen(line) );
    
    sprintf(line, "Content-Type: application/x-www-form-urlencoded\r\n");
    client.write( (const uint8_t*)line, strlen(line) );
    
    sprintf(line, "title=%s&msg=%s\r\n", title, msg); //this is the POST data
    client.write( (const uint8_t*)line, strlen(line) );
    
    //Wait till there is any data and then read it
    unsigned long lastTime = millis();
        
    while( client.available()==0 && millis()-lastTime<20000) { //a 20 second timeout
        char c=client.read();
        response[pos] = c;
        pos++;
    }
    response[pos]='\0';
    
    Serial.println(response);
    //Again check if there is still anything left in the buffer
    while (client.available()) client.read(); 
    client.flush();
    
    delay(500);//wait till the request is completed to avoid race condition
    client.stop();
    
    }

Again how can I be sure as to how long I will have to wait before performing a read() and stop(). Because you can never be sure as how long your script is going to take.

Also this function is called from a interrupt routine and if I am correct I cant use delay() inside an ISR.

Please let me know your opinion on this.

[UPDATE] : Getting multiple red flash after calling the function and the core restarts.The response I get from the php page is "Motion detected @ Jan 16th 03:44:49 PM". This is just to let you know that the response does not use much memory.

Can anybody please please help me for a working implementation of the above function.

Thanks