Satic Occluder behaving as occludee

Hello,
I am trying to utilize occlusion in a way that it only culls smaller, unimportant, items (so the map itself won’t be occluded, occlusion is too inaccurate to be used on such large meshes).
Map section marked as Occluder-only not rendering.
Sadly it appears that even though I set my mesh to occluder static and disabled being an occludee, it still gets culled when not looking away (and sometimes when looking at it).
The settings of the mesh itself.
Can anyone help me? I am in dire need of using occlusion but I wish for the map itself to remain unculled.
Thank you in advance.

I guess not.