The devices are not removed. They still connected to the hub and work. But HUB became very slow. I had this issue not once already and according to support the hub is slow because z-wave network is not working properly.
Sorry, I probably was not clear. I had to remove affected devices and pair them back in past. This is not the first time I am having this issue. I don;t recall if I had to force the removal or I was just able to remove. I am hoping to avoid to removing devices this time. Because that is really a lot of work. Was hoping some one may have better solution or idea how to prevent this from happening over and over.
Ok, probably you are a victim of ghost nodes, I was victim too, but fixing this without deleting anything you must use a 3rd party program and of course is not recommended by the staff because you can scew up more the mesh if you don't know what are you doing.
7 of my smoke detectors are like this and they are working fine. Hub is running normal as well. Just commenting in case your issue is elsewhere. Contact support and they will probably sorted out quicker.
Those are not dead devices, the data displayed on that page is stored in the device data and is reloaded on boot. It is only gotten from the device at join time and we no longer query the device for that data at boot up. If you can check the device page and post what your device data section is showing? it should look something like this: