When a device is offline and you click the X to disconnect it, it stays in the list of offline devices. You cannot edit a hostname once you set a device with a reserved IP. Few other minor issues as well.
Can you please have them push out a firmware update that will address the missing connected devices as well as these issues?
It is really annoying when trying to setup your network the way you want it. Like making a mistake with an IP or hostname. It cannot be changed without a factory reset. That is pretty ridiculous to be honest.