Kind of a weird problem. About 3-4 years ago, I put in a GE smart-z-wave switch in my basement and two of the add-on switches. The z-wave switch is at the top of the steps - the other two switches are in the basement. This was originally with a Wink hub (not really important - just stating that it worked fine)
When I switch over to Hubitat, it discovered the z-wave switch and worked. If I press the add-on switches, they turn on/off the light as expected. Fast-forward a few months - the z-wave switch was acting weird. It would randomly turn on by itself. The add-on switches no longer control it.
I originally replaced the add-on switches since the z-wave switch could turn on/off and Hubitat controls it. No luck - addon switches still could not control it.
This weekend, I replaced the z-wave switch with a Honeywell z-wave plus switch. Before I paired it with Hubitat, I tried out the add-on switches. They work. They can turn on/off the switch. Expected behavior. However, I'm happy - the wife has been nagging me about the lights not working right for some time.
I discovered the new switch with Hubitat and it can control it. Cool! All done. I was then leaving the basement and pressed the add-on switch to turn off the light. Nothing.
Sorry for the long story. Basically, the add-on switches can control the z-wave switch before I paired with Hubitat. After pairing with Hubitat, the add-on switches do not do anything.
Good news - the new z-wave switch no longer randomly turns itself on.
Am I missing something? I looked at devices and do not see anything obvious. The wiring has not changed since I did the original installation (and when I replaced the z-wave switch, everything is still wired correctly).