Adding extra room to Evohome

[Thunder614]

Running: Domoticz build 14880 on Raspberry Pi using Docker
Honeywell Evohome via Web API, Evotouch controller

I have multiple rooms defined in my Evohome and these are visible and controllable from Domoticz. However, I have recently added an extra room to the Evohome system and would also like to control it from Domoticz. That does not seem to work. When I go to Hardware - Evohome via Web API - Create Devices, it asks whether I want to create a controller, zone or hot water. I choose Zone, it says the sensor has been created. But no new device is visible in the devices screen.

Is there anything I can do to add it? I don't want to lose the logging of the existing rooms, otherwise I would have completely removed the hardware and re-added it.