error: connection failed

I'm struggling with my Lolin32 using a waveshare 2.9 after changing the network configurations. I just set up a new wifi network and now the Lolin32 causes some problems while establishing the wifi connection. I receive the following error:

Connecting to: **SSID**
WiFi connected at: 192.**********
connection failed, error: connection failed, error: connection failed, error: connection failed, error: _PowerOff : 153004
Entering 1778-secs of sleep time
Awake for : 3.755-secs
Starting deep-sleep period...

I already tried out a easy Wifi test on my Lolin32 and it worked perfectly. It connected to the network very smoothly and had a stable connection. The code I used for this test is the following:

#include <Arduino.h>
#include <WiFi.h>

void setup() {
  Serial.begin(115200);
  WiFi.begin("**SSID**", "**password**");

  // Wait for wifi to be connected
  uint32_t notConnectedCounter = 0;
  while (WiFi.status() != WL_CONNECTED) {
      delay(100);
      Serial.println("Wifi connecting...");
      notConnectedCounter++;
      if(notConnectedCounter > 150) { // Reset board if not connected after 5s
          Serial.println("Resetting due to Wifi not connecting...");
          ESP.restart();
      }
  }
  Serial.print("Wifi connected, IP address: ");
  Serial.println(WiFi.localIP());
}

void loop() {
  // put your main code here, to run repeatedly:
}

Does somebody know about any differences in the "Waveshare_2_9_v4.ino" that could probably cause my problem?

G6EJD / ESP32-e-Paper-Weather-Display

error: connection failed #209