I have a C7 hub running 2.3.7.146 (Just updated to .147)
This started a few weeks ago, where my commands do not work to control z wave devices. I first noticed it with rules that should turn lights on/off at sunrise/set, then realized it was all zwave. What is odd, is if I manually change the device at a switch, I can see that on/off status instantly on my hub page. Zigbee devices are fine.
The only way I was able to get it working again, was a 30min unplug and restart. A quick restart or shutdown didn't do it. I also checked for ghost devices and removed the only 1 I had, but its probably been there far longer than the problem. I thought that power down fixed the problem, but it started up again tonight after about a week.
Even when it was working it was sluggish for some commands, but while slow they at least worked. Its almost like the zwave network is getting clogged, but I assured that I dont have any extra things running like power, etc.