Faraway client cannot connect

I'm from Viet Nam and I'm just getting started with PUN 2. I'm building an simple app and all my friends in Viet Nam can connect and run properly. The problem is, a friend from Canada cannot pass connecting phase.
void connect ()
{
connecting.SetActive(true); //a text saying "Connecting"
PhotonNetwork.GameVersion = gameVersion;
PhotonNetwork.ConnectUsingSettings();
}
void override OnConnectedToMaster { do things };
Her client show the text forever and output_log.txt doesn't tell anything.
Is there something must be done to deal with different regions?
Thanks in advance :3