Problem getting html data from Websites ESP8266

I got a code here.(C++)

At the website: "github.com" the code works fine and I get the index of "meta" = 53

As soon as I change the address to for example "timeanddate.com", I get the index (-1) = no result.

My question: What is the difference between these two websites?

"meta" is included in both HTML source pages both are HTTPS What's missing?

Tests:

https://github.com = HTTP Status: 200 Index: 53.00

https://www.timeanddate.de = HTTP Status: 200 Index: -1.00

https://timeanddate.de = HTTP Status: 302

https://www.timeanddate.com = HTTP Status: 200 Index: -1.00

https://timeanddate.com = HTTP Status: 301 Index: -1.00

P.S. with google.com it even crashes

#include <Arduino.h>
#include <ESP8266WiFi.h>
#include <ESP8266WiFiMulti.h>
#include <ESP8266HTTPClient.h>
#include <WiFiClientSecure.h>

#define   SSID_NAME                 "XXXXXXXXXX"                                                                             
#define   SSID_PASSWORD             "XXXXXXXXXX"  


ESP8266WiFiMulti WiFiMulti;
//WiFiClientSecure client;
HTTPClient https;
BearSSL::WiFiClientSecure client;




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

  WiFi.mode(WIFI_STA);
  WiFiMulti.addAP(SSID_NAME, SSID_PASSWORD);

  //Connect to WIFI
  Serial.print("Connecting to ");
  Serial.print(SSID_NAME);
  Serial.println(".");
  Serial.print("Waiting for Wifi to connect...");
  while (WiFiMulti.run() != WL_CONNECTED){
    Serial.print(".");
    delay(1000);
  }
  Serial.println("  Done.");

  IPAddress ip(192,168,0,172);   
  IPAddress gateway(192,168,0,1);   
  IPAddress subnet(255,255,255,0);   
  WiFi.config(ip, gateway, subnet);


}

void loop() {
  int code = 0;
  double bodyTag;

     client.setInsecure();
     client.setTimeout(8000);

      https.begin(client,"https://www.google.com");

      code = https.GET();
      while (code != HTTP_CODE_OK){
        Serial.print("HTTPCODE FAIL: ");
        Serial.println(code); 
        code = https.GET(); 
        delay(500);
      }

        Serial.print("HTTP Status: ");
        Serial.println(code);

        //Check if KeyWord is Found in Search.ch
        bodyTag = https.getString().indexOf("meta");
        Serial.print("Index: ");
        Serial.println(bodyTag); 
        delay(5000);
}