@DimiFox,

Unforutnately, Private Addressing is difficult to identify and block. This feature is something that will be coming soon to Decos in the next major firmware update. You can get a preview of the features in this forum post for the Deco 1.9.0 firmware update. On Archer Routers, this is only currently possible because the Access Control features you see are tied with the ARP binding table, rather than working with solely IP and MAC addresses.

Currently, the feature is being tested and will begin rolling out with the X55, however we do not have a specific timeframe regarding when your model may receive the update.

Furthermore, the ability to deal with these private addressing settings will improve with coming updates separate from what you see in the above posting. 

For now, you will need to try and disable the Private Addressing or Randomized MAC on your devices so that you can see whenever new "devices" are being added to the network. Once the setting is disabled, you can then set an IP reservation for the device since it will tie an IP address to the devices MAC Address

  @DimiFox,

There are quite a few benefits to them if they disable it for your home network, not just for your own 'tracking' - so you may suggest it.

• The handshake doesn't have to occur between the devices, along with the security scan - meaning devices can quickly reconnect and will be able to smoothly roam between nodes. Imagine the confusion your network has if your phone changes address while the network is trying to switch between Deco nodes...
• Your Deco can work to make sure that the devices you use most often will have the best connection.
• Random MACs may change periodically, causing interrupted sessions
• You will likely need to login to services more often, as your phone is "changing" networks each time.
• Tracking and Targeted content may use this information to identify your device. causing less accurate recommendations

I think hat this was something that was more common / easier with regular router setups, as mesh systems oftentimes do not have the full whitelist settings - hence why Archers can do exactly what you are looking for. From what I can tell, the coming features will be extremely easy to use and will work exactly the way you would like.