I have an Airport Time Capsule at one location and an Airport Extreme with attached hard drive at another location. My iCloud account is associated with each device via "Back to my Mac" in the settings of each router. I use to be able to view the contents of each router wherever I was from my Macbook Air. Now, I can no longer access them unless I am on the same network for each. I think this might be a MacOS Sierra problem. I never heard of a router being configured to access a laptop remotely. Usually it is the laptop that accesses the router.