Black and Pink Navmesh

Hi,
I have a game where npcs hunt players. I had a lot of problems with the navigation and so far I’ve only found out that black and pink are the best solution for obstacles that the NPC’s avoid.
But still I think the black Navmesh works worse than the pink one.

So my question is, how can I make every obstacle in a pink navmesh? Since Pink is working the best for them.

I placed 2 different fences next to each other as in the picture with the same settings “can be damaged” off, that’s it. although, the one on the left shows a black navmesh.

Unfortunately there is nowhere I could find anything about it. I would appreciate help with the situation.