I just installed a UniFi AP-AC-Mesh last week. When I view the UniFi AP-AC-Mesh statistics via my controler, no data appears, but I can see it in https://unifi.ubnt.com/?
Here is via my controller:
And here is via https://unifi.ubnt.com/:
Check the date range - the local controller doesn't update automatically. Little bug...
Well when I view in Chrome on a PC, it shows up. Not in Chrome on a MAC. Maybe a broswer bug...