Adding on from what was already mentioned . .
If you're still experiencing issues whenever you log in using the login system, you can try different web browsers, one of them being Chrome since that's a popular one along with Firefox. You can also try logging into your cellular / mobile device, if you have one, keeping the page up and running like that before logging into the game.
On top of this, you can try getting a tab refresher so that way it doesn't kick you off too often. ^^
Sorry if this is a lot at once, but this is just the basics at least. I could add more, but I don't want to overbear you with a lot of information. ^^;
Hope this helps ~?