Cookies not working like they should but they work on localhost?

[Greenreader9]

You set secure to true
https://www.php.net/manual/en/function.setcookie.php

But your website is served over HTTP - so that cookie request is blocked:

(See the Restrict access to cookies section)

Using HTTP cookies - HTTP | MDN

You need an SSL certificate:

How to make your website use HTTPS (SSL)

So you want your website to use HTTPS. You want to secure your website and enjoy the search engine benefits. In order to get that sweet padlock, there are a couple of things you need to do. Install an SSL certificate Before your website can use HTTPS, you need to have an SSL certificate for your domain name. You will need to get this SSL certificate from an SSL certificate vendor and install it on your hosting account. You can install your certificate using the SSL/TLS section in your control …