Occlusion culling visibility lines going through objects

Hello.
I tried to set occlusion culling on my scene but for some reason when i try to debug occlusion, i can see that some visibility lines are going straight through objects, part of terrain and a lot of objects are visible even if they shouldnt. Everything on my scene is set as static so there should be no problem with objects not marked as occluder/occludee. I tried set default parameters for baking and even some very low (like occluder:1 hole:0.1) but there is almost no result in this bug. I even tried to play with backface threshold but that doesnt do anything too. I also tried to create Occlusion area/Occlusion portal every 20m on whole map just to see if it will be different but no result in this particular issue at all.
I find out that there are people that have also similar issue here but for some reason noone from Unity answered their issues.
Does anyone know how to fix this problem please?

(Im also sending screenshot where i marked with red where occlusion is working correctly (building stopped lines) and yellow where its obvious that lines are going incorrectly through object)