cannot resolve destination host

When I play in my brother's house, i have many bug in my game. My game lag and sometime during 30s/1min my game freeze in differents moments (battle, interaction with png , dialogue for headbutt or dig ...). Sometime i must close my game and re-open it. My brother have very good internet connection (optical fiber), better than mine and when i play in my house i dont have any problems.

He dont have these problems with his computer so i dont understand.

I see thing which maybe can explain this, so I tell you if it can help you to understand my problem.

When i open my game, in the 1st screen with downloading when it say that "our version is the latest" or something like this, there is a message in red which say "cannot resolve destination host".

If this have any link with the problems ?

Thank tou for help

ps : I'm French so sorry for my English, i do my best.