This is something you can trigger a rule off of. See Thing Status Reporting [3.2.0;3.4.9] which is a rule template you can install and instantiate a rule which will call a rule you write with a list of all the Things that have gone OFFLINE.
That can give you an alert or execute a script to take remedial actions if it’s one or more of the Zwave Things.
That’s going to take more info. In particular I suspect you’ll want debug logs from the Zwave binding around the time that it goes offline.