Suggest adding a few more always-on Zigee Router devices that always have power (preferably some dedicated Zigbee Router products or DIY devices) see -.> Zigbee networks: how to guide for avoiding interference + optimizing using Zigbee Router devices (repeaters/extenders) to get best possible range and coverage
The make sure avoid EMF/EMI/FMI interference suggest also connecting the Zigbee Coordinate USB adapter via a long USB 2.0 extension cable to a USB 2.0 port or a powered USB 2.0 hub, (do not connect it to a USB 3.0 port unless using a USB 2.0 cable, and even then it is better to use a USB 2.0 port or a powered USB 2.0 hub).