I have 3 823LM wall light switch controls, and all have worked fine for about 8 months. Recently one of them stopped working via the iOS app but still works via the wall switch. I cleared it with the learn button and re-paired it to the gateway. I completely reset the gateway and reinstalled everything. I tried to reset the switch by keeping the breaker off for an hour. All of these efforts went fine but the light will still not trigger via the app. Any suggestions? Thanks!