@KhairulAlam this is the most requested feature for the last 3+ years and zero progress and zero response from Tp link about that :(

It is really frustrating to see several notifications daily that UNKNOWN has connected, then immediately going into the list of all devices and not seeing it there (even after refresh) and there is also no history log of all devices making connection...

How are we supposed to troubleshoot that (e.g. identify the device and rename it as suggested in other comments)?

I realize that desirafeature that would block all new devices from accessing network by default might be a bigger change (still not as big to not be able to deliver over past 3+ years), but why TP Link cannot, at least, add a MAC address of the device (the "UNKNOWN") into the notification message? This would allow us, owners, to do the homework on our end and identify that rogue device that drives us nuts...

  @Juve 

I have a theory and that at least I solved it.

It turns out that android devices today have an option enabled by default that is the random MAC, changes every so often and the tplink at first does not recognize it until you see the name of the device then only associates and disappears the device "unknown".

I disabled the random MAC on android devices and never saw an "unknown" device on my Tp-Link network again.