Arduino send GET request to server on local network

Question

I have a local network composed of 2 devices:

1. Raspberry Pi running Raspbian with an Apache server. (IP 169.254.90.117)
2. Arduino MEGA with an Arduino Ethernet Shield. (IP 169.254.90.110)

The 2 devices are directly connected via Ethernet cable.

What I want to do is pretty straight forward: be able to send a GET request from the Arduino to the server hosted on the Raspberry Pi in order to modify records on a database.
Unfortunately every time I try Arduino fails to connect to the server and the serial console shows this:

Initialising...
Trying to connect to server
connection failed

I know that the Raspberry server is working because I tried connecting the Raspberry to a PC from which I was able to navigate with a browser to the website hosted on the server without any issues.

I also tried pinging the Arduino from the Raspberry and the ping is successful.

After navigating through a few forums I tried changing the variable type on the Arduino where I saved the server's IP from a normal char variable to a byte and a IPAddress but with no success.

Here's the Arduino code I've been using:

#include <SPI.h>
#include <Ethernet.h>

byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
byte ip[] = { 169, 254, 90, 110 }; 

char server[] = "169.254.90.117";
//byte server[] = { 169, 254, 90, 117 };
//IPAddress server(169,254,90,117); 

String HTTP_METHOD = "GET";
String PATH_NAME   = "/setNumber.php";
String queryString = "?test=26";

EthernetClient client;

void setup() {
  Serial.begin(9600);
  
  Serial.println("Initialising...");
  Ethernet.begin(mac, ip);
  
  // connect to web server on port 80:
  Serial.println("Trying to connect to server");
  if(client.connect(server, 80)>0) {
    // if connected:
    Serial.println("Connected to server");
    
    // make a HTTP request:
    // send HTTP header
    client.println(HTTP_METHOD + " " + PATH_NAME + queryString + " HTTP/1.1");
    Serial.println("Sending GET: " + HTTP_METHOD + " " + PATH_NAME + queryString + " HTTP/1.1");
    client.println("Host: " + String(server));
    client.println("Connection: close");
    client.println(); // end HTTP header

    while(client.connected()) {
      if(client.available()){
        // read an incoming byte from the server and print it to serial monitor:
        char c = client.read();
        Serial.print(c);
      }
    }

    // the server's disconnected, stop the client:
    client.stop();
    Serial.println();
    Serial.println("disconnected");
  } else {// if not connected:
    Serial.println("connection failed");
  }
}

void loop() {

}

EDIT:

I've updated the char variable to a char[] array but the result is still the same.

To verify that the Arduino Ethernet Shield was working properly I connected it to the internet and succesfully sent a request to www.google.com.