What happened to my switch?

I don't understand what's going on.
I have a Leviton switch, called Downstairs Steps. I have a few other switches that go on, when I turn on that switch. I've turned on that switch many times today.
Why doesn't it show up in the events of that switch, that I turned it on?
The following shows NO events for today: (2019-05-21):

Furthermore, there are no entries in my past logs for this device. (Which I don't understand!)
In addition, I can turn on the switch from the device edit panel, by pressing the ON button.
However, even after I do that, the device still says OFF!

What happened to my switch?

So, at some point in my IT career, I was in charge of a Customer Response section. This is the response that I would have Support give to this individual who reported that his switch stopped working.
(In ascending order of hardest to implement):

  1. Reboot the Hub, and do a a z-wave repair. (Always a first response).
    If that doesn't work:
  2. (a) Do a z-wave exclusion on the switch.
    (b) If that doesn't work, do a factory reset on the switch.
    (c) Then do an inclusion on the switch.
    (d) Repair all automatons to work on the "new" switch.
    (e) Force remove the "old" switch.
    (f) Z-wave repair as a last step.
    If that doesn't work:
  3. Rip the old switch out of the wall, and replace.

If the switch stops working again, at some point in time in the future, you may wish to go directly to step #3.

Change 2 to be an exclude first before any attempt at a factory reset. Doing a rest first leaves a ghost device.
I assume your response was because no one responded. If you really have a support issue, you should be emailing support@hubitat.com.
Assuming you did your step 1, what was the result?

Thanks for the response.

I did Step #2, and it is now back in service. Maybe the z-wave chip just got tired, and is "old" in "dog years". If it happens again, I go straight to #3.

(I will edit my point #2 to make it clearer).

I don't know how many devices you have and how they are placed but Zwave devices really want to have many ways home (neighbors).
I would look at the lay of the land so to speak and try to understand where that switch might route through, what might interfere with the communications.

One of the things that I originally proposed to support was to make publicly available z-wave "maps" technology, so that we could visualize the z-wave environment. The Zensys tool appears to be the most common way of visualizing the zwave topology.

I have an Aeotek Zstick that I have paired to the HE hub. The stick is installed on a virtual Linux machine running Open Zwave Control Panel (OZWCP). I get Zwave logging and a reasonable insight into how things are running. I modified a script I was using with HomeAssistant to get hops and neighbor information.