The Offline Bug.. Potential Solution..
This is a very common bug that's seems to affect everyone..I'm not sure when they will address this critical bug as it's making the game almost unplayable... Almost..
There is a work around. You need mobile and a computer.
If you are able to log into one of those devices.. and then load up the game on the other device and try and log in
It should boot you from the previous device and this may or may not fix the issue temporarily.
Fiddle around going into the game on both devices simultaneously... Eventually it will work again. The key is to be able to log onto one in order to boot you from the other device.
Try it out.. do it vise versa and just keep trying. I've managed to play several games normally. It's a hit or miss.
Once your logged in.. and it's working.. try and keep the game open and don't log out.
Hope this helps