@MoJaKh You can check the place that sold you 3-unit Deco X20, they might sell single units. TP-Link Deco availability is region specific, so unless you live in the same country I am this is the best...

@MoJaKh Yes, you can add 4th Deco unit to your Deco mesh. It makes sense to add same type of unit, so that hardware is consistent. That means, X20 is the best choice.

@RoomTiger Deco unit has multiple MAC addresses, because it has Ethernet card and wireless. The one that is on the bottom sticker of device is its Ethernet MAC address. Still, I am not sure what MAC...

@Cobretti302 To fix this issue permanently, the first step should be to configure NAS request dynamic IP address. If you remember how you configured it with static IP before you had Decos, that might...

@StuartMoss "New Device Detected" is one of overlooked but very useful TP-Link Deco features. While this time it were false alarm, if ever someone connects to your WiFi network without your...

@StuartMoss This message says that someone who knows your WiFi network password successfully connected their Samsung Galaxy S8 device to your WiFi network. You should have seen this device as active...