Twitch started lagging for me on highest settings (even on +480p streams) around 2 weeks ago, now since 2 days ago I can't even access the site without VPN. help.twitch.tv is fine, the rest won't load at all or just in text form after about 30 minutes. I can view the stream fine when the site loads via VPN and I turn it off for actual stream.
ISP: Kabel Deutschland (30 down / 2 up)
Browsers: IE, Firefox, Chrome, Opera, Safari. Doesn't matter, it won't load. Flash is up to date.
I've already contacted my ISP which said to me that it's not on their end and they "will look into it" (ie they won't do anything).
They’re actually in contact with us about this, I guess they didn’t notify their tier 1 support about that (surprise!). Thanks for the update.