Light switch is not responding but is recognized by app

I have a number of switches throughout the house. All of them are working fine except for one of them which stopped responding today. It is an inovelli NZW30. It is a simple single pole on off light switch. It has been installed and working absolutely fine for weeks. Today, it stopped responding to the app. I used the app to remove and then re-add it. I have repaired the z-wave network multiple times. If I manually turn the light on or off, the app instantly recognizes that and shows the change in status. Yet nothing I do can get the switch to respond to the app. Any ideas?