At the graphical interface level, sometimes the On/Off does not work (it remains stuck in the same position). I encounter the problem with different connected Z-Wave outlets. Switching to another tab or refreshing the page allows to fix the problem. In the logs, I have this:
2020-04-16T21:23:18+0200 <debug> scene.executeSingleAction.js:15 (SceneManager.executeSingleAction) Executing action of type device.set-value
2020-04-16T21:23:18+0200 <debug> zwave.setValue.js:13 (ZwaveManager.setValue) Zwave: Setting value
2020-04-16T21:23:18+0200 <debug> zwave.valueChanged.js:14 (ZwaveManager.valueChanged) Zwave: Value Changed, nodeId = 20, comClass = 37, value = {"value_id":"20-37-1-0","node_id":20,"class_id":37,"type":"bool","genre":"user","instance":1,"index":0,"label":"Switch","units":"","help":"Turn On/Off Device","read_only":false,"write_only":false,"min":0,"max":0,"is_polled":false,"value":true}
2020-04-16T21:23:18+0200 <debug> zwave.valueChanged.js:16 (ZwaveManager.valueChanged) node20: changed: 37:Switch:false->true
2020-04-16T21:23:18+0200 <debug> device.saveState.js:16 (DeviceManager.saveState) device.saveState of deviceFeature zwave-switch-nas-wr01ze-power-plug-12a-node-20
2020-04-16T21:23:18+0200 <debug> zwave.valueChanged.js:14 (ZwaveManager.valueChanged) Zwave: Value Changed, nodeId = 20, comClass = 37, value = {"value_id":"20-37-1-0","node_id":20,"class_id":37,"type":"bool","genre":"user","instance":1,"index":0,"label":"Switch","units":"","help":"Turn On/Off Device","read_only":false,"write_only":false,"min":0,"max":0,"is_polled":false,"value":true}
2020-04-16T21:23:18+0200 <debug> zwave.valueChanged.js:16 (ZwaveManager.valueChanged) node20: changed: 37:Switch:true->true
2020-04-16T21:23:18+0200 <debug> device.saveState.js:16 (DeviceManager.saveState) device.saveState of deviceFeature zwave-switch-nas-wr01ze-power-plug-12a-node-20
The bug is visible on the second to last line.