I've got the same issues it worked fine until I changed ISP and now it's not working, what I don't understand is that there is no issue when playing other games online. I still play dayz through a glitch I use to join a server were I turn my console offline then online again and during that time frame when it's reconnecting it will let me connect to a server, I don't like doing it because it's a pain and I should be able to join normally. I've done everything possible, reset IP address, reset xbox and restarted my router and none of its worked. Changing ISP isn't an option either. Please and thank you for your support.