I’m still in the process of setting up Home Assistant for the first time. After successfully adding an Aeotec Zstick and one lamp switch module I went and configured the Google Assistant component. Following the instructions on that component’s hass page everything worked and I can now turn that one lamp switch on and off with a voice command.
I’ve since added a number of other zwave switches, but they don’t yet show up in Google Assistant. Going to Settings -> Home control -> Devices I can see the first lamp switch, my Nest thermostats, some Chromecasts, etc, basically everything that I had set up before configuring Google Assistant in hass. But none of the recently added devices are present.
I think I’ve read somewhere that this is not needed anymore, although you have to call a service, don’t remember which, sorry. I’ll try to find the thread.