No WIFI connection with my ESP8266.

C++
#include "ESP8266WiFi.h"

const char* ssid = "xxxx";
const char* password = "xxxxx";

void setup() {
  
  // initialize serial and wait for the port to open:
  Serial.begin(115200);
  Serial.println("connecting to ");
  Serial.println(ssid);

  // attempt to connect using WEP encryption:
  WiFi.persistent(false); // solution found on a forum but does not work
  WiFi.setAutoReconnect(true); // solution found on a forum but does not work

  WiFi.mode(WIFI_OFF); // solution found on a forum but does not work
  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
    ///network search
    Serial.println("network search ");
    int n = WiFi.scanNetworks();

    Serial.println("start done  ...");
    if (n == 0) {
      Serial.println("no network found ...");
    } else {
      Serial.print(n);
      Serial.println("network found");

      for (int i = 0; i < n; i++) {
        Serial.print(i + 1);
        Serial.println(":");
        Serial.print(WiFi.SSID(i));
        Serial.println(" (");
        Serial.print(WiFi.RSSI(i));
        Serial.println(")");
        if (WiFi.encryptionType(i) == ENC_TYPE_NONE) {
          Serial.println(" ");
        } else {
          Serial.println("*");
        }
      }
    }
    /// end of network search
  }
  Serial.println("");
  Serial.println("WIFI connected ");
  Serial.println("Local IP address: ");
  Serial.println(WiFi.localIP());
}

void loop() {
}

C++
#include "ESP8266WiFi.h"

const char* ssid = "xxxx";
const char* password = "xxxxx";

void setup() {
  
  // initialize serial and wait for the port to open:
  Serial.begin(115200);
  Serial.println("connecting to ");
  Serial.println(ssid);

  // attempt to connect using WEP encryption:
  WiFi.persistent(false); // solution found on a forum but does not work
  WiFi.setAutoReconnect(true); // solution found on a forum but does not work

  WiFi.mode(WIFI_OFF); // solution found on a forum but does not work
  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
    ///network search
    Serial.println("network search ");
    int n = WiFi.scanNetworks();

    Serial.println("start done  ...");
    if (n == 0) {
      Serial.println("no network found ...");
    } else {
      Serial.print(n);
      Serial.println("network found");

      for (int i = 0; i < n; i++) {
        Serial.print(i + 1);
        Serial.println(":");
        Serial.print(WiFi.SSID(i));
        Serial.println(" (");
        Serial.print(WiFi.RSSI(i));
        Serial.println(")");
        if (WiFi.encryptionType(i) == ENC_TYPE_NONE) {
          Serial.println(" ");
        } else {
          Serial.println("*");
        }
      }
    }
    /// end of network search
  }
  Serial.println("");
  Serial.println("WIFI connected ");
  Serial.println("Local IP address: ");
  Serial.println(WiFi.localIP());
}

void loop() {
}