deco not showing all connected devices
I have always been able to see all connected devices on my network thru the deco app. Recently some devices are showing up on the offline list but they are actually connected. I have added a new device to my network as well and had to approve its connection but it does not show up anywhere on any list that it is connected. When I log into the router thru the web based site it shows connected devices and real time activity but the Connection is " - " where other devices show them connected to either 2.4 or 5.0 wireless. Wondering why this has all of a sudden happened? I have password on my wifi but could someone hide new devices without accessing my deco set up which has a totally different password. Is there a way to know if someone has set up a vpn or private network?