Zwave integration of FGS

This is my first time with HA.
I have added Z-Wave JS, which has discovered 10 devices.

  • 5 FGS223
  • 5 “nodes”

In reality I have 7 FGS223 installed! and I do not understand why they are not seen, as they are physically very close to the others (same room). Is there a way ?

I have no clue what the “nodes” are! How can I know?

As I have some free FGS221, I ve tried to get them discovered as well. But no way! Restarting the Zwave server does not help (the number of devices and nodes remains 10), and using the “add device” button ends up with a timeout message. Activating the inclusion button of the FGS does not help!

I would be of course very pleased to be helped!!