It’s a known problem with this brand as they age. Doesn’t affect every switch maybe 15%. Much discussion on the forums. I’m too tired right at the moment to dig out the topics for you, but it was recently discussed at length in the following thread. You’ll have to read down a ways to get to the discussion about them falling off the network.
There are two fixes that work for most people.
One) cut the power to the circuits at the switches on then restore. Not just of the switch, at the breaker. That’s often enough to fix it. For a while anyway.
There are two fixes that work for most people.
One) cut the power to the circuits at the switches on then restore. Not just of the switch, at the breaker. That’s often enough to fix it. For a while anyway.
Two) pretend like you removed that switch and replaced it with one of the identical model, even though you actually leave the original switch in place. Just run the “Z wave replace” utility from the smart thing as mobile app or from the IDE if you have the windows act like you remove that switch and replaced it with one of the identical model, even though you actually leave the original switching place. Just run the “Z wave replace” utility from the smartthings mobile app or from the IDE if you have the windows phone app. Just doing that seems to fix it for some people, although most seem to also need to do the circuit breaker cycle.
good luck, I know it’s frustrating.