NavMesh Tile Height and Nav Area Behaviour

Hey everyone,

so i’m a bit puzzled about the following behaviour:

as you can see, my ai agents are punching a hole in the navmesh (to fix issues with the detour crowd avoidance), which triggers a rebuild of their corresponding tile in the navmesh. That seems all good, but for some reason in infinite direction up and downwards the tiles are also “rebuild” (assuming that is what the red flashing means). But i can’t find any setting that would stop that from happening, everything “tile height” related is way less than that. I understand that neighbor tiles might need to be updated as well, but this seems way more than just neighbors.
So there is either the assumption from the navmesh generator, that games are more horizontal than vertical, or a setting which i could not find.

Another issue that i think might be related is about Nav Mesh Modifier Volumes.
I have multiple in my world, kinda like a very primitive flow field. Most of it works fine, but this time the nav area “bleeds” vertical outside the volume. While i get that the nav area is never perfectly aligned to the volume (also apparent from the pictures), guessing that’s because of the error tolerance and nav mesh generator, this is far too much off.

from the front. As you can see the volume is only on the stairs, not on the gallery above.

What seems to be happening here is that the bounding box, even it is rotated, is transformed to an encompassing axis aligned one. Because when i move the highest point of the volume(the left side at the top of the stairs) below the gallery floor, the incorrect nav area disappears on the gallery.

Hope somebody can help me with those 2 issues or explain why this is happening.

Thanks in advance!

bump.