It was happening to me as well, but I found a fix for it, well at least for me anyway. A Microsoft domain was being blocked by my computer. To check if it's the same problem in CMD ping vortex.data.microsoft.com , if it does ping but requests fail (and you are still having issues with achievements) then this isn't the fix for you, if it does NOT attempt to ping at all then we know what the problem is. The way I dealt with the problem was resetting my Firewall and then going into the host file in windows (this could be wherever you have installed windows) If you don't know where it is go into System32/drivers/... and look for the 'hosts' file. (you can simply search host in the search bar up top when in System32) Once this is done open it with whichever program file editor you are most comfortable with, I used Notepad++ because it is free and extremely useful. When you are in the file and you can read it properly simply delete the 0.0.0.0 vortex.data.microsoft.com line and save the file, it will ask you to run in administrator mode as you are editing windows files, just tap yes. And you should be good to go once you start up the game.
The only problem I am having now, is trying to obtain the achievements the game has already recognised before completing this fix. As I would attempt to do certain task like aiming a weapon without a scope to get the binary number achievement and it does not register on steam. I am assuming this is because the game has already ticked it off the list and it just isn't communicating that already finished list with steam. If anybody could help me with this problem, I would be a very happy little spartan.