ESP8266 Connection Issues with 2 DHCP Server

Hello Guys,

I have an issue with My Adafruit Huzzah Feather (ESP8266). I try to connect it to a WIFI Acces Point. But the network has 2 DHCP Servers in case of a DHCP-Failover. So the problem is that the Huzzah is trying to connect but without success (Picture 1). If I turn off one of the DHCP servers then it works just fine. There are no issues with the network itself because every other OS based Device like a raspberry pi or a computer can connect even if there are 2 DHCP Servers. I guess it is some service that the huzzah is missing or something and because of that, he can not handle the answer of the DHCP when it tries to give it an IP. If I print the wifi status it is showing the 6 so it is clearly not connecting (Picture 2).

#include <ESP8266WiFi.h>
#include <ESP8266WebServer.h>
#include <ESP8266mDNS.h>

void setup()
{
Serial.begin(115200);
Serial.println();
pinMode(LED_BUILTIN, OUTPUT);

WiFi.disconnect(true);
delay(20);
WiFi.mode(WIFI_STA);
delay(20);

WiFi.setPhyMode(WIFI_PHY_MODE_11N);
WiFi.mode(WIFI_AP_STA);
WiFi.hostname("IotONE");
WiFi.begin("my-ssid", "my-password"); // <<-- ändern
MDNS.begin("IotONE");

Serial.print("Connecting");

while (WiFi.status() != WL_CONNECTED)
{
  delay(100);
  Serial.print(".");
}

Serial.println();
Serial.print("Connected, IP address: ");
Serial.println( WiFi.macAddress() );
Serial.println( WiFi.localIP() );
Serial.println( ESP.getChipId() );
}


void loop()
{
heartbeat (500);
}


void heartbeat (unsigned int interval)          
{
static unsigned long last_ms = 0;
static bool state = LOW;

unsigned long ms = millis();

if (ms - last_ms >= interval) {
  last_ms = ms;
  state = !state;
  digitalWrite(LED_BUILTIN, state);
}
}

Could you please read the top few posts in this section of the forum then modify your post to put your sketch in CODE TAGS ( </> )
Thanks.

Bob.