LOS/visibility issue

I'm having trouble getting LOS blocking to work properly on a map. In one area, I have a narrow passage with a line of LOS blockers running across it, yet units have no difficulty seeing past it. In another area, I have a gate that should block LOS, but which doesn't (the gate has an occlusion height of ~300, which is more than trees, so I'd expect it to block sight fine). There are no fliers, and both black mask and fog of war seem to be working properly. There are no visibility modifers or any other funky stuff that would mess with visibility. Can anyone offer any insight into what's going on here or suggest possible solutions?

LOS blocking is dependent on the doodad's pathing. If the pathing only affects air, it will only affect air unit LOS.

Although I did not, in fact, know that, as mentioned above, that wouldn't be an issue, as ALL units involved are ground units. Moreover, as mentioned above, there is a gate, which presumably blocks ground travel, which does not block LOS as it should. Anyone know what's going on here?

I'll have to do some testing. It's possible taht you may have to put the gate in the pathing blockers category.