It's more than likely that you have poor Internet service, until you get reliable, steady Internet it will happen. Also it could definitely be router related, using a router causes these issues. Plug your Ethernet cable directly into your Internet modem, don't use a router.
If your wiring is older in your house then that can also cause connection issues.
Do other people share your Internet connection? What happens with this is that there is a heavy flow of information streaming all at once which will cause you to lose Your connection just long enough to disconnect you from the game. I can almost tell you for sure that it's not really server sided, as easy as is it is to just blame the servers.
I guarantee one of these factors apply to each of you, correct the issue or it will just happen. Just going to have to accept that.