Sooo if your like me and have a top of the range PC with decent internet and an open NAT and have spent many of hours on threads trying to fix your disconnecting issues only to find that none of the threads and help posts seem to work because they 1. Dont really relate too your issue or 2. You have gone and done everything too your PC that the thread suggests and still no luck. I hope this helps. So when you buy a custom built PC from a tech shop, 9 times out of ten the computer is gunna have some hardware apps that allow you too control your PC whether it be overclocking, boot up, the RGB setup etc. What also comes with some of the apps are applications that let you control the internet priority for apps on your PC. My app was called Killer control panel. Since uninstalling that application my disconnecting issues have disappeared. So if you have a 3rd party application controlling the priority of your internet, try uninstalling it and see if it works. I hope this helps possibly a couple of people. Note: If this works i think it might have something to do with destiny's no 3rd party applications rule and it might be what is causing the issue.