I would restart the hub and any switches you have tried to update around the same time, thats what seemed to help for me. If you have an "air gap" disconnect pull that to restart the switch otherwise you have to hit the breaker to turn it off.
For it turning off by itself make sure you don't have the auto-off parameter set. I had one of mine doing that then I noticed in the logs it way staying on for exactly an hour. Somehow I had enabled the auto-off. Check out my driver if you need access to the advanced settings: [RELEASE] Zooz ZEN Switches Advanced Drivers
