I have found an interesting thing in the last month, some days connection was fine and others I seemed to be a bit behind other players. What I found was that even though I am connected via ethernet, sometimes the xbox would default to the wifi connection causing the lag. Since there is no easy way to turn off wifi connection on xbox one, I was forced to log into router from my phone and disable the wifi which made a night and day difference. Logged on last night and had a delay on my grenade throws, disabled wifi (even though it showed wired connection) Xbox showed lost connection but I was still in party with team mates and the lag was gone. Just something to try if you are having issues.