Does the device show the correct timezone? This is part of the reply from the weather service. Also, the sunrise and sunset times under the forecast page (clicking the weather icon on the home page) will show the controller’s sunrise and sunset times for the current weather (future days are calculated in the app).
Are you using a static IP on the device? If so, what is your gateway IP? Do you have any firewall appliances possibly filtering OpenSprinkler weather requests?
Just some thoughts to try and troubleshoot, thanks.