When my wireless devices, at the moment it’s a 2014 mac laptop and my android phone, wake from a sleep state i’m unable to access the internet via these devices.
During my “did I turn it on and turn it off again diagnostic crud”, I swapped the devices over to a cellspot router sharing the same physical network, and it works fine. When I swap back, most of the time the back and forth swapping restores usability to the UBNT WiFi.
This wasn’t always the case, it seems recent. I’ve only had the mesh setup in the house for about 4 months.
Power cycling the UBNT devices doesn’t seem to resolve the issue. The connectivity upon wake state thing only seems to affect me when using UBNT WiFi. 
I really want to get away from this craptastic cell spot router but I may have to keep it around.
It almost seems like clients and the wifi devices are caching some kind of bogus state that prevents internet connectivity somehow.