When communication between your AP and the Meraki Cloud is blocked, the AP reports "Alert: This device is having difficulty contacting the Meraki Cloud". If you see this alert in Dashboard, follow the KB article below:
If this does not fix the issue, a traffic inspection security setting may enabled on your ISP supplied modem or router. Sometimes rebooting the modem or router will temporarily fix the issue. Comcast modems or routers manufactured by SMC have the "Gateway Smart Packet Detection" security feature which is known to cause this condition and comes enabled by default.
If your network is experiencing this issue, contact your ISP or modem/router manufacturer for assistance in disabling the security feature.