Request returns http instead of https

12

Yes, Cloudflare is the cause. As far as your webserver knows, it is http because of the port number.

Are you trying to generate a URL from Twig? If so, override $uri when creating the TwigExtension.

        $view->addExtension(new Slim\Views\TwigExtension(
            $c->get('router'),
            'https://example.com'
        ));

See this discussion for a very similar topic and solutions.