Guys the issue has been found by myself. I've suggested a fix and have gotten hundreds of messages saying it worked. I have gotten some saying that it doesn't. I'll post below what i've come up with... My router settings have never changed since I started playing this game. Having said that I found a fix that is working for me. I logged into my router and it has 2 settings for upnp. 1: UPNP - Internet Gateway Device (IGD) / NAT-T 2: UPNP - Universal Plug and Play / SSDP Since day one i've used option number 1. Changed to option number 2 and i'm now able to join a friends fireteam thats on my network. Seems to me bungie has has it set so anyone using UPNP - Internet Gateway Device (IGD) / NAT-T can't connect to someones fireteam that is on the same network. Not sure if this was done on purpose or what but it's working for me. Now for some this did not work because their router does not have the option to changed between the 2 UPNP protocols. [u][b]DR REPRISE[/b][/u] has posted a solution for that which further backs what I've said since a computer uses both protocols. I'll post the link below where he explains and you can see my comments below. His solution is to use a mac but you can find instructions on how to do it on a PC until bungie fixes it. https://www.bungie.net/en/Forums/Post/213700713?showBanned=0&path=0