There has been episodes of extremely bad connectivity that made it impossible to play the game. I suspect this may coincide with server maintenance schedules. The connection tends to come on suddenly and lasts 2 or 3 days and spontaneously resolves. This pattern of periods of connection issues followed by spontaneous resolution by itself has been reported previously a few times myself.

There has been no formal address or contact by SG to resolve or look into this matter. Any ticket to service support churns a generic reply to re download the game app etc. It doesn't acknowledge there may be a server problem etc on their end, always assumed a customer phone or wifi issue. 

Its getting very frustrating and SG should look into this urgently.