I have the same issue since firmware update (2.1.9 & 2.2.0).
It does not matter if you use Dark Sy or Weather Underground. After a x period of time the Weather Service is ‘offline’. When you restart the controller and wait a few seconds, the Weather Service is online.
It looks like this has nothing to do with the Weather Service but with the Wifi-internet connection. Accessing the controller is no problem.
I have sent several support e-mails but so for no solution.
It is very annoying that the Weather Service its offline because Watering Lever is not accurate anymore.