OwnTracks not updating device_tracker state to zone

Currently running HomeAssistant v0.100.2 in a Python 3.6.4 venv on Ubuntu Server 18.04 and using a Nabu Casa subscription including the OwnTracks webhook integration.

I’ve realised recently that my device_tracker states are not reflecting the current zone they are in.
They only ever show ‘home’ or ‘not_home’ rather than the expected work zone name when within the zone.

I should not that:

  • zone entry and exit triggers fire correctly for each tracker
  • map displays correctly for each tracker
  • device trackers report accurate gps co-ordinates
  • no errors reported in the HA logs.

Having trawled the community and previously reported and closed github issues I can see that this scenario has occurred in the past.

Can anyone else using OwnTracks advise whether this the expected current state of affairs?