Issue with Z-Smoke 230V by Heatit

I have several of these smoke alarms Heatit Z-Smoke Detector 230V - Heatit

For some reason a couple of the alarms some times seem to become unavailable on the z-wave network. Once they report back on shortly after then the binary sensor for smoke detected reports as on. This triggers the automation I have for smoke detection with alerts, phone calls etc.

The alarm itself does not trigger but it’s the default state once the device rejoins the network which appears to be the issue. I have to go back into HA states and set the state again to off.

Any ideas?