Can not remove EUROtronic Spirit Z from Z-Wave

My system is a raspberry pi 2b with Raspbian 10 (buster) running Kodi and Home Assistant in Python Virtualenv, recently upgraded to Home Assistant 0.100.1.

There are three nodes in my Z-Wave network. A Z-Wave.Me ZME_UZB1 USB Stick, a Fibaro Wall Plug and the Spirit Z Thermostat, which I want to remove. All nodes are awake and ready.

To remove I clicked to the config area, down to z-wave and hit the node remove button. Then I pressed and did hold the button on the thermostat as described in the Spirit Z manual for at least 5 seconds. The device showed “LEA” on its display and then switched back to showing the current temperature setting point, instead of “INS” as described in the manual.

I can see nothing suspicious in the ozw log however:

2019-10-10 23:09:55.140 Always, OpenZwave Version 1.4.3440 Starting Up
…
2019-10-10 23:22:24.744 Detail, Queuing (Controller) Remove Device
2019-10-10 23:22:24.745 Info, Remove Device
2019-10-10 23:22:24.746 Detail, contrlr, Queuing (Command) ControllerCommand_RemoveDevice: 0x01, 0x05, 0x00, 0x4b, 0x81, 0x32, 0x02
2019-10-10 23:22:24.746 Detail, Notification: ControllerCommand - Starting
2019-10-10 23:22:24.747 Detail, 
2019-10-10 23:22:24.748 Info, contrlr, Sending (Command) message (Callback ID=0x32, Expected Reply=0x4b) - ControllerCommand_RemoveDevice: 0x01, 0x05, 0x00, 0x4b, 0x81, 0x32, 0x02
2019-10-10 23:22:24.753 Detail, contrlr,   Received: 0x01, 0x07, 0x00, 0x4b, 0x32, 0x01, 0x00, 0x00, 0x80
2019-10-10 23:22:24.754 Detail, 
2019-10-10 23:22:24.754 Info, FUNC_ID_ZW_REMOVE_NODE_FROM_NETWORK:
2019-10-10 23:22:24.754 Info, REMOVE_NODE_STATUS_LEARN_READY
2019-10-10 23:22:24.755 Detail, Node001,   Expected callbackId was received
2019-10-10 23:22:24.755 Detail, Node001,   Expected reply was received
2019-10-10 23:22:24.755 Detail, Node001,   Message transaction complete
2019-10-10 23:22:24.756 Detail, 
2019-10-10 23:22:24.756 Detail, contrlr, Removing current message
2019-10-10 23:22:24.756 Detail, Notification: ControllerCommand - Waiting
2019-10-10 23:22:24.757 Info, WriteNextMsg Controller nothing to do

Is this the supposed way to remove that kind of device? I want to remove it from the radiator and replace with a non Z-Wave device, but remove it from the Z-Wave network correctly first, so it can be added to a different Z-Wave network later.