Thank you for your reply,
I haven't played anything this past month except DOTA 2 but I tried Playing S4 League which I also encounter lag and spiky latency. But it is worst this days, hope you can fix this because I am not the only one encountering this issue.
Speedtest shows a good result. Ping to google public DNS and Facebook.com seems good too (although with spikes).
About the troubleshooting, I have done all posible things I could do. I bet I did because I work as a network engineer
I also have the same issue, my packet loss goes to 10-25 percent. And a ping of 100-170 ms.