I wonder if you've tried: controlled shutdown/pull power to hub/wait 30 seconds/plug power back in to hub ?
I have not, I'll try that later.
Also, the latest device I added is a Zen16 multi relay that was giving me problems when I used ST. I wonder, if that's the culprit... No old Jasco devices though.
Is there any tool that snoops on the zwave traffic, so I can see every message that the hub sees? I wonder if there's a device failing and flooding the network with bogus traffic that overwhelms the zwave radio on the hub.
In the meantime, I'm replacing everything zwave device I can with zigbee. zwave has been nothing but a pain, my ST zwave mesh failed so spectacularly that made me move to Hubitat...
Go to your Z-Wave Details page under Settings. Could be you may have created a Z-Wave Ghost or two when trying to add the Zen16 (or another of your Z-Wave devices). If you post a screen shots of your Z-Wave Details page we can help you ID any issues (including ghosts) that are there.
Oh wow, this is super detailed. I do have a few ghost nodes I tried to remove without success. I'll try the approach to power down the hub first, see if that works.