My wife told me that one of the Zigbee buttons wasn't working correctly; upon investigation, it turned out that none of our Zigbee devices were working.
To the hub, then. Nothing in the Log; on the "Zigbee Details" page, I saw "Zigbee Network State: OFFLINE" (although "Enabled"), and "Zigbee Channel" set incorrectly. I tried both "Disabled" and "Enabled", and changing the channel back to 20, but none of that changed anything.
So, reboot the hub. And, BOOM, everything back the way it was supposed to be (Enabled, 20, all functioning).
C-5 running 18.104.22.168. Never happened before, and hoping it never happens again; WAF took a massive hit.
Yeah that's happened to me too for both ZB & WAF.. on my old main C-4. I did also have some faulty Z-Wave devices back then that were causing trouble so maybe there was some system/resource issue that caused the ZB service to crash dunno.