Well, this is really hard to tell — the fact that weather calls are fine and water programs are working means the controller itself is alive. Slow connection speed can be related to many factors — for example, the signal strength may be weak; or there may be a compatibility issue of the WiFi chip (ESP8266) with your router. Have you tried to use the OpenSprinkler mobile app to connect and see if it goes faster? If the problem still persists, you can submit a support ticket.