cannot reach esp8266 via udp while he is running with a static ip

#include <ESP8266WiFi.h>
#include <WiFiUdp.h>

const char* ssid = "your_SSID";
const char* password = "your_PASSWORD";
const IPAddress ip(192, 168, 1, 100); // Replace with the desired static IP
const IPAddress gateway(192, 168, 1, 1);
const IPAddress subnet(255, 255, 255, 0);

const unsigned int localPort = 12345; // Choose a UDP port
WiFiUDP udp;

void setup() {
  Serial.begin(115200);

  WiFi.config(ip, gateway, subnet);
  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Connecting to WiFi...");
  }

  Serial.println("Connected to WiFi");

  udp.begin(localPort);
}

void loop() {
  int packetSize = udp.parsePacket();
  if (packetSize) {
    char packetBuffer[255];
    int len = udp.read(packetBuffer, 255);
    if (len > 0) {
      packetBuffer[len] = 0;
      Serial.print("Received packet: ");
      Serial.println(packetBuffer);
    }
  }
}