these manuals are not obvious, everythnig I did to set up my zwavejsui was trial and error... (also the command to start zwavejsui didnt work on my Rpi, I had to modify the command I used for zwavejs2mqtt to have persistent configuration) Get the key from Domoticz (mine was just ...

Check out this one:
viewtopic.php?p=264337#p264337

This is what helped solve my problem - and hopefully future ones as well though it's more a kinda workaround: I modified options.xml (/domoticz/Config) by setting <Option name="ReloadAfterUpdate" value="NEVER" /> which prevents a new z-wave devices config file to automatically modify existing nodes ...

Is this causing the problem? Log says:
2020-12-23 16:02:02.841 Status: OpenZWave: User Alert - Manufacturer_specific.xml out of Date

see viewtopic.php?t=28569

I have some annoyances too wrt z-wave. And they take too much time fixing it. It's frustrating. What I experience is that devices pop up out of nothing. In my case this only happens with temperature sensors on a Fibaro Binary Sensor (FGBS001 type 501 id 1002). It is not battery-powered by the way ...