Login issue

The worst newest PoGo updated version. For the first time i get the notice: "Failed to get data from the server" i thought its my wifi connection (but it wasn't). The second time, i logged in the game, and out the game cause schooling time then i login and continue get the notice. The third time, i logged in in the game, everything just fine, ok for a test, i did logout and re-login again and the cursed notice appeared. Ofcourse this is not a ban its just a server connection.
Anyone else have this problem like me? Please tell me how to fix it? (T-T)
P/S: I must wait for serveral minutes to get back in the game again ...