WiFi.dhcpServerIP() and WiFi.dnsServerIP() don't return an IP

I’ve implemented a basic HTTP server with a About This Device page, everything is working fine except I can’t seem to get the DHCP or DNS server IP addresses. I read the documentation which says Particle.process() needs to be called once WiFi has connected to get the DHCP and DNS server addresses but even still I’m unable to get the address. Am I doing something wrong? The method i’m using is:

void APDSHTTPServer::sendAboutResponse()
    Particle.process(); //Required to get DHCP server address
    aboutResponse.messageBody.concat("IP Address: " + String(WiFi.localIP()) + "</br>");
    aboutResponse.messageBody.concat("Subnet Mask: " + String(WiFi.subnetMask()) + "</br>");
    aboutResponse.messageBody.concat("Gateway: " + String(WiFi.gatewayIP()) + "</br>");
    aboutResponse.messageBody.concat("DNS Server: " + String(WiFi.dnsServerIP()) + "</br>");
    aboutResponse.messageBody.concat("DHCP Server: " + String(WiFi.dhcpServerIP()) + "</br>");