esp8266 NodeMCU client cant connect to esp8266 NodeMCU server with static ip

Hello...

My code is working perfect with using dynamic IP's, the LED is connected to server and a push button is connected to client, it work perfect with dynamic IP's addresses of both devices. But when i make static IP addresses, the client can not connect to server, and it always says connection failed.

Client code is:

#include <ESP8266WiFi.h>
//IPAddress staticIP612_61(192,168,100,59);
//IPAddress gateway612_61(192,168,100,1);
//IPAddress subnet612_61(255,255,255,0);
const char* ssid = "GravixarATD";                  // Your wifi Name       
const char* password = "TheRedMonster79"; // Your wifi Password

const char * host = "192.168.100.23";        // IP Server

const int httpPort = 80;

const char* Commands;                       // The command variable that is sent to the server                     

int button = 5;                             // push button is connected
bool btn_press = true;                      // The variable to detect the button has been pressed
int con = 0;                                // Variables for mode

void setup() {
  // put your setup code here, to run once:
  pinMode(button, INPUT_PULLUP);            // initialize the pushbutton pin as an input:
  Serial.begin(115200);                     // initialize serial:

  Serial.println("");
  Serial.println("Client-------------------------------");
  Serial.print("Connecting to Network");
  WiFi.mode(WIFI_STA);                      // Mode Station
  WiFi.begin(ssid, password);               // Matching the SSID and Password
  delay(1000);

  // Waiting to connect to wifi
  while (WiFi.status() != WL_CONNECTED) {
    Serial.print(".");
    delay(500);
  }
  Serial.println("");
  Serial.println("Successfully Connecting");  
  Serial.println("Status : Connected");
  //WiFi.config(staticIP612_61, gateway612_61, subnet612_61);
  Serial.print("IP address: ");
  Serial.println(WiFi.localIP());
  Serial.println("-------------------------------------");
  Serial.println("");
}

void loop() {
  // put your main code here, to run repeatedly:
  
  if (digitalRead(button) == LOW) {
    Serial.println("Client-------------------------------");
    Serial.print("Send Command = ");
    if (btn_press == true){
      if (con >= 2) {
        con=0;
      }
      con++;

      switch (con){
        case 1:
          Commands="LED_On";
          Serial.println(Commands);
          send_commands();
          break;
        case 2:
          Commands="LED_Off";
          Serial.println(Commands);
          send_commands();
          break;
         
      }
      
      btn_press = false;
    }
  }
  else {
    btn_press = true;
  }
  delay(100);
}


void send_commands(){
  Serial.println("Sending command...");
  Serial.println("Don't press the button for now...");
  Serial.println("");
  Serial.print("Connecting to ");
  Serial.println(host);

  // Use WiFiClient class to create TCP connections
  WiFiClient client;
  
  if (!client.connect(host, httpPort)) {
    Serial.println("Connection failed");
    return;
  }

  // We now create a URI for the request  
  Serial.print("Requesting URL : ");
  Serial.println(Commands);

  // This will send the request to the server
  client.print(String("GET ") + Commands + " HTTP/1.1\r\n" + "Host: " + host + "\r\n" + "Connection: Close\r\n\r\n");
  unsigned long timeout = millis();
  while (client.available() == 0) {
    if (millis() - timeout > 5000) {      
      Serial.println(">>> Client Timeout !");
      client.stop();
      return;
    }
  }
  
  Serial.print("Server Reply = "); 
  // Read all the lines of the reply from server and print them to Serial
  while(client.available()){
    String line = client.readStringUntil('\r');
    Serial.print(line);
  }
  Serial.println("Now you can press the button ...");
  Serial.println("-------------------------------------");
  Serial.println("");
}

Server code is:

#include <ESP8266WiFi.h>
//IPAddress staticIP612_60(192,168,100,60);
//IPAddress gateway612_60(192,168,100,1);
//IPAddress subnet612_60(255,255,255,0);
int led = 5; // the pin the LED is connected to

const char* ssid = "GravixarATD";                  // Your wifi Name       
const char* password = "TheRedMonster79"; // Your wifi Password
const char* Commands_Reply;                 // The command variable that is sent to the client

const char * host = "192.168.100.21";          // IP Client

WiFiServer server(80);

void setup() {
  // put your setup code here, to run once:
  pinMode(led, OUTPUT);                     // Declare the LED as an output
  Serial.begin(115200);                     // initialize serial:
  delay(10);

  Serial.println("");
  Serial.println("Server-------------------------------");
  Serial.print("Configuring access point");
  WiFi.begin(ssid, password);

  // Waiting to connect to wifi
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
    Serial.println("");
    Serial.println("WiFi connected");
    // WiFi.config(staticIP612_60, gateway612_60, subnet612_60);

  // Start the server
    server.begin();
    Serial.println("Server started");

  // Print the IP address
    Serial.print("Use this URL to connect: ");
    Serial.print("http://");
    Serial.print(WiFi.localIP());
    Serial.println("/");
    Serial.println("-------------------------------------");
    Serial.println("");
}

void loop() {
  // put your main code here, to run repeatedly:
  // Check if a client has connected
  WiFiClient client = server.available();
  if (!client) {
    return;
  }
  
  // Wait until the client sends some data
  Serial.println("Server-------------------------------");
  Serial.println("New client");
  Serial.print("From client = ");
  while(!client.available()){
    delay(1);
  }
  
  // Read the first line of the request -------------------------------------
   String req = client.readStringUntil('\r');
   Serial.println(req);
   client.flush();

   //Command LED -------------------------------------------------------------
    
   if (req.indexOf("LED_On") != -1){
      Commands_Reply = "LED Status : On";
      Serial.print("Server send = ");
      Serial.println(Commands_Reply);
      client.print(String("GET ") + Commands_Reply + " HTTP/1.1\r\n" + "Host: " + host + "\r\n" + "Connection: close\r\n\r\n");
      digitalWrite(led, HIGH);
    }
   else if (req.indexOf("LED_Off") != -1){
    Commands_Reply = "LED Status : Off";
    Serial.print("Server send = ");
      Serial.println(Commands_Reply);
      client.print(String("GET ") + Commands_Reply + " HTTP/1.1\r\n" + "Host: " + host + "\r\n" + "Connection: close\r\n\r\n");
      digitalWrite(led, LOW);
    }
   else {
     Serial.println("invalid request");
     client.stop();
     return;
    }

   client.flush();
   Serial.println("Client disonnected");
   Serial.println("-------------------------------------");
   Serial.println("");
}

NOTE I have commented all the static IP lines, when i comment them and using dynamic ips, client connect to server perfectly and when i use static ips instead of dynamic ips client fails to connect with server. any help will be appreciated.