It’s hard to say what’s up here - no devices are responding so it seems to be a network problem. Communications between the binding and controller is find, but between the controller and the device is not fine.
I would suggest to reset the stick by unplugging it.
After few resets and re-inclusions I find out the problem. The physical relay was next to a big metallic layer and that seems to block/modify the Z-Wave signal enough to break the connection with the controller.