You are seeing POI circles at 13 km ? interesting ... I admit i havent really tested the upper limit of the circles ... am usually hovering around that 2km - 1.7 area trying to see the little buggers before deciding if i want to land.
I'm doing all my scouting between 5 and 15kms above the surface and ordinary blue circle PoIs show up on your radar at those heights. Fixed PoI's (at least the one I visited in Orrere) do not have a blue circle.