There is a known problem with some people that are on the same network getting into a fireteam together. That said, chat is separate from Destiny and is a Xbox feature. Since you are having both issues with local fireteams and chat parties you may have a completely separate issue going on. First WiFi is bad for gaming and horrible for Destiny because of it requirements for a highly stable connection. I'd highly suggest getting permanently hard wired, at the very least you need to hard wire to troubleshoot properly. Check the network guide. Make sure your routers' settings are correct, you may need to look up the manual for your router to figure out how to set the needed settings. I suggest using UPNP instead of port forwarding. Make sure your NAT is open. Set static IPs for box Xbox consoles. Change the name of the Xbox consoles, by default they are both the same and this can cause issues on a network. UPnP/Port Forwarding/NAT Type - Allowing Destiny's Connections https://www.bungie.net/en/Help/Troubleshoot?oid=13612 GETTING CONFIGURED: A GUIDE TO CONFIGURING YOUR NAT SETTINGS. https://www.bungie.net/en/Help/Article/11931 Network Troubleshooting Guide https://www.bungie.net/en/Support/Troubleshoot?oid=12915 Change Xbox Name To access the system settings, navigate left on the Home screen to open the Xbox Guide, select Settings, and then select All settings. Under Console Info and Updates is the section to change the name.