I played Left 4 Dead 2 in US before. Then I went to China and played it, it automatically switched to connect local server in China I think.
However, when I went back to US and chose to
play campaign -> play online again. It shows all campaign games created by Chinese players. It didn't switch back to US server automatically.
Connecting campaign games created by Chinese players in US is very slow.
How can I show campaign games created by American players again? I didn't find any place where I can switch the server.