What dashboard are you using? (Web, iOS, Android)
What OS? (Jessie, Wheezy)
What Model Pi?
At work we are provided with a general wifi network for browising internet. When the pi is connected at home, the dashboard works good, but when connected at work, dashboard is showing offline, yet full internet access is available on the pi. Could it be that Cayenne, uses certain ports that the work network is blocking?
Wifi connection: I connect to the work wifi network with an android phone (as it takes care of the PEAP enterprise protocol) and tethered the internet connection to the pi via usb. As mentioned, I can browse the internet etc.