Arduino Uno + W5500. Pings ok but can't always connect through browsers

Hello. I have a very old Netbook that I plan to use as a desktop clock and weather station. It will display a local html page that will get weather readings in json format from different sensors (outside and indoors) and have js scripts manipulate that data. I base my sketch on Ethernet library server example and on ArduinoJson library example.

//v 0.2

#include <ArduinoJson.h>
#include <Ethernet.h>
#include <SPI.h>
#include <AM2320.h>



 
byte mac[] = {0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xE0}; 
IPAddress ip(192, 168, 1, 150);
EthernetServer server(80);

AM2320 thermometer; 


void setup() {
  
  Ethernet.init(10);  // Most Arduino shields
  // Initialize serial port
  Serial.begin(9600);
  while (!Serial) continue;

  Ethernet.begin(mac, ip);

  

  // Start to listen
  server.begin();
  delay(1000); //waiting for server to set up
  Serial.println(F("Server is ready."));
  Serial.print(F("Please connect to http://"));
  Serial.println(Ethernet.localIP());
}

void loop() {
  //runs++;
  float myTemp = thermometer.t;
  float myHumidity = thermometer.h;
  // Wait for an incoming connection
  EthernetClient client = server.available();

if (client) {
    Serial.println("Got a client");
    
    // an http request ends with a blank line
    boolean currentLineIsBlank = true;
    while (client.connected()) {
      if (client.available()) {
        char c = client.read();
        // if you've gotten to the end of the line (received a newline
        // character) and the line is blank, the http request has ended,
        // so you can send a reply
        if (c == '\n' && currentLineIsBlank) {
          StaticJsonDocument<200> doc; 

  doc["spot"] = "outside";
  doc["temperature"] = myTemp;
  doc["humidity"] = myHumidity;
  
 //Serial.println("step1");
  //Serial.print("Sending: ");
  serializeJson(doc, Serial);
  Serial.println();

          // send a standard http response header
          client.println("HTTP/1.1 200 OK");
         client.println("Access-Control-Allow-Origin: *");    
  client.println("Content-Type: application/json");
  client.println("Connection: close");
  client.println("Refresh: 10");
  client.print("Content-Length: ");
  client.println(measureJsonPretty(doc));
  client.println();

  // Write JSON document
  serializeJsonPretty(doc, client);
  break;
        }
        if (c == '\n') {
          // you're starting a new line
          currentLineIsBlank = true;
        } else if (c != '\r') {
          // you've gotten a character on the current line
          currentLineIsBlank = false;
        }
      }
    }
    // give the web browser time to receive the data
    delay(10);
    // close the connection:
    Serial.println("DEBUG1");
    client.stop();
    Serial.println("DEBUG2");
  }
      
}

With the above code Arduino ALWAYS pings but many times visiting 192.168.1.150 through any browser (for debugging) gives me "Can't connect".

Any thoughts?

Does the netbook have a static IP?

Does it hibernate?

Hello. Thanks for your reply. The netbook is not in the picture yet, I am testing data at the moment on my other machines by visiting 192.168.1.150. Ping works all the time, but many times browsers don't. I suspect it's a switch - router thing, but I am open to suggestions.