That sounds very strange, although some people have reported similar issues in the last month or so. But not if you were just toggling it in the mobile app.
Do you see anything in the device log in the mobile app? You go to rooms, then you select the device, and then you can see its recent activity. You can also look at the other logs if you want to dig into it:
Meanwhile, I would definitely report this to support@smartthings.com there’s nothing in Zwave itself that would cause a 20 minute delay, that almost has to be some kind of cloud issue.
Thanks JD. I’ll get more details later. Here is what I noticed. Twice now…the switch won’t turn off when you toggle it in the ap so I think “must be a reception issue etc” but, when I run a routine such as “all lights off” it responds. My guess is that would be a cloud issue?
There’s always a possibility that it’s an intermittent interference issue, so that the signal can’t get through it sometimes, like when you turn on the microwave and Netflix starts buffering. But that doesn’t seem to fit what you’ve been describing. And we know that other people have been having cloud-based issues with state not being reported correctly in the app. So it does seem more likely that it’s the cloud.