Dota 2 Lag when I play, but not when I alt-tab out

I get this issue every once in a while. By once in a while I mean maybe once every 1-2 month. And when it happens, it stays about 1-2 days. Then it's fine.

Like, when I check ping in "server choosing" tab, it shows ~30ms. But in game it's no less than 80ms.
When I alt-tab, I can see it goes down immediately to ~30ms.

Whatever I do, like openning folder, other app, as long as I am not in the game, I can see ping going down to ~30ms. But will immediately go up to ~80 when I switch back.
It is happening to both my Ethernet and mobile LTE through tethering. And INSANE LAGGING/HANG during spec ulti or MK's ulti. No, not my computer going frozen or anything, but it's like internet disconnect for 1s - 2s.

Other game like CSGO seems to be fine.

 

Never had issue like you described, but I must say I too experienced many times some lag during MK's ulti.
Do you have any package loss? Maybe you have some problems with network infrastructure in your home.

 

packet loss is like daily meal to me. But this mk/spec ult lagging only happens when I have issue as stated above.

 

which server are you on? it happens in SEA commonly...just one of those things that cant be helped.

 

Yep. SEA

 

Recently it seems like Valve hasn't been turning their heads to problems in the game for awhile.

Hope your problem get's solved, try going into task manager and disabling any unnecessary applications!

 

It is solved now. It happens every once in a while. So there's no root of the issue, no fix, just random moment server goes crazy.