core: zwave_js regularly showing almost all powered and some battery devices as "unavailable"

The problem

Recently upgraded to ZWave-JS from OZW1.4 using zwavejs2mqtt as WS interface and for CP (no MQTT) and it is at 99%. I notice that almost all of my powered nodes (the sensor node, i.e., the old zwave.node) shows unavailable nearly always. I can do a heal network from the integration panel, or a heal node from the CP, which sometimes works to set them to alive, but the soon return. Some battery-powerd devices report unavailable as well, although most report asleep. Either something is not getting reported by the server, or the integration isn’t receiving an update, or not reporting it to the UI. Note that all of the devices marked unavailable work as expected, and if I click on the device, the Device status always says Node Status: Alive and Node Ready: Yes. The zwave.node entities in OZW1.4 always showed Ready.

What is version of Home Assistant Core has the issue?

core-2021.8.6 ; zwavejs2mqtt v0.23.4

What was the last working version of Home Assistant Core?

No response

What type of installation are you running?

Home Assistant OS

Integration causing the issue

zwave-js

Link to integration documentation on our website

No response

Example YAML snippet

No response

Anything in the logs that might be useful for us?

No response

Additional information

No response