Welcome to the community, @AlbaVerrat. Please this comment. 
So, It does show when the device is off-line. But that means I need to continuously look to see if it is off-line. The app apparently knows it is off-line so, how hard would it be to send a message it is off-line? I have a remote building that it would be nice to know when I loose power in the middle of winter.
Thumbs up from me about getting an automated message when it isn’t connected.
Lost connection would likely be power out on that circuit
You can try using IFTTT and write a little simple code to alert you.