From Microchip Received Signal Strength

[river moon]

What about RSSI? In my case it's "Unknown" both at the coordinator and ED. Is it normal?
And I"m curious about effective distance. Is there any rule of thumb?

[cerulean saffron]

It's often not enabled by default. On the device page look for E.g. +2 entities not shown, click and each open the dialog and enable