Hi! Does WebThings have the concept for a stale/disconnected device, and if so does the Gateway have a visual indication (like a grayed out Thing) of that state? I ask because I have a Zigbee temperature sensor whose temperature is definitely out of date, likely because it’s been days since the Gateway has gotten a message from it, but the Thing doesn’t have any indication of a problem. I’m interested in determining if that’s a bug, or simply just functionality not implemented/supported yet. If it’s a simple thing I may attempt implementing it myself 
With SmartThings it grays out the device, changes the state label to “Offline”, and on the detail view has a message saying “Device disconnected.\nCheck to see if the device has power and is operating normally. If the device is still disconnected, try adding the device to SmartThings again”