GetRandomReachablePointInRadius seems to be not working properly

Hello,

I’m actually using GetRandomReachablePointInRadius in order to spawn some actors:

However the problem I have is that most of the actors spawned are in the same area, even if the map are reachable in many other places when I check the navigation area in green with “P”.

As you can see on the screenshot, I have spawned 15 actors in total (they are green little objects).
The RED zone contain 13 actors
The BLUE zone is the reachable area (reachable by AI by the way). Other zones like roofs are not.

Maybe someone can help ?
I’m actually using UE5.2

Thanks a lot !