Me and my girlfriend had the same issue, we are both in the same house installed at the same time and setup and all exactly the same; obviously on the same router; but I was running it fine while she was getting 1000000 desync, sometimes come out of it and be able to play for a little while longer before yellow/redchaining and then it'd reoccur and battleeye would kick her for no response or something close to that effect, turned out she needed to go to the battleye homepage and download it directly for whatever reason and replace it in the steamapp/common/dayz dir whatever folder it's in, the top pinned post in this forum shows how to do it. Since then she hasn't really had a problem at all at least with full disconnects. I noticed some desync myself at times (but never full disconnects) on some highpop servers (20-40 players) that'd skyrocket to 1000000 for somewhere between 20 seconds to 2 minutes to be rather common and YET seemed fine low pop (0-6 players) only to desync and get a yellow/red chain for shorter periods and far less often but of course still be attacked by invisible zombies or bug through the floor of buildings, all at complete RANDOM and then be fine again at 30-50 ping.. then it'd happen again at random.. and rinse-repeat. So on low pop maybe go between 20-60 minutes without an issue, high pop was more akin to 2-15 minutes. I thought at first it was just 'alpha' and nothing could be done, figured the servers were buggy and that was that but... for the sake of making things more playable.. Ended up disabling my firewall to get no improvement; meanwhile she'd not have the issue WHILE i'm having it, she'd be pointing on her screen at a zombie I couldn't see! Then it'd happen to her, but not to me.. so once the firewall thing failed to help we both went into 'Game mode" in our firewall and that fixed it entirely, been running fine without a single lag-glitch or rubber-banding since. (Do not ask me why disabling the firewall did nothing, but game mode for the past several days has made it run flawlessly.. I'll never grasp that one.) All in all IMO it's worth direct-downloading battleeye and finding out where to install it; testing the game > if it still has any issues disable your firewall & try again > see if your firewall has a game mode and try that > if all that fails, uninstall your firewall altogether and test it again; if THAT works maybe it's time to find a new firewall. If none of that works, I'm at a loss. Sorry'