For the past week I have been experiencing higher than usual MS and random disconnects, only with blizzard games.
Just to clarify what this means, I will be doing a m+ run with friends, while on discord and watching a stream on 2nd monitor. WoW will then lag, my character can still move around but not cast anything and then I will get disconnected with a WOW51900319 error and Bnet will go offline mode. While this is happening my discord is completely fine as me and my friends are still talking, no lag whatsoever, and the stream I am watching is still fine (not my game streaming, a random twitch stream).
I have talked to my ISP, and what they have said is that a node in the routing is not receiving packets from Blizzard, and that it is not my ISP’s fault.
I would like some help with this as it is driving me crazy, I cant do any content (raids, m+, visions) as I can get randomly disconnected and affect others’ playing experience.
I have pastebin links of WinMTR but apparently I cant post them…
Assuming you have read this support article here.
Also for the WinMTR, you would make a ticket here and upload that file.
Already done, though I dont expect much to come from it.
Its painfully obvious from the traceroute that the issues happen outside of my ISP’s network, mainly with the Telia nodes in the UK through which I am routed (that’s where the packet loss starts), but Blizzard never like to admit the fault might be on their side; its always the customer’s ISP that is at fault when it comes to these things.
Took this as disconnect happened just now. https://pastebin.com/RQp11aVS . Yes the ip where packetloss and high ping happens is in UK, blizzard ip. But its never their fault.
Dc from game and battle net client.
High ping on a blizzard ip cause for disconnects
Keep getting dc'd from Blizzard games - #6 by Supremedruid-tarren-mill
Well I noticed something with this issue, when I get dc’d the bnet client always goes offline and then reconnects.
So I bypassed it and accessed wow directly from the retail folder, without logging into the bnet client. I’ve been playing for a few hours today and so far no disconnects.
I dont know if this means the issue is with the authentication servers or whatnot, but you can give it a try and see if it helps you.
I would just wait and see what Blizzard say, if they haven’t already responded.
I hope it gets resolved for you. 
Blizzard will not say anything on this matter, because they will never admit it might be on their end. I sent clear cut traceroutes with the issue being pointed out as being outside of my network, their response “its your ISP’s fault, their connection to the faulty nodes is the problem, talk to them”. This is besides the fact that other people in other parts of the world are having the same problem, some of them being from the US (same issues on wow US forums). I have coincidentally talked to my ISP several times, they told me the same thing, once the outside of their network, the game data is routed by Blizzard, whatever path that may take. At this point the only thing people can do is wait for it to be fixed, however long that may take.
Hey every one. No im not from russia, just play on russian server. I have same problem and reading other post, GM says it could be because of beta version of battle.net app, but im using standard old one. But yeah, some players from russia have same problem. But as i understand, problem is with battle.net app.