Lumen in interior

I´m working on my first game in UE5 and I have problem with lighting or with Lumen.

I have weird black glitch if I run arround the corner. I don´t know if I have some settings wrong or where is the problem. I tried some solution which I found but nothing helped.

The walls are from small blocks, but they have overlaps, but if I make small room from these walls without light inside the light still goes throught in Lumen Scene view. I tried make these walls thicker, but this didn´t help me with black glitch and also I need these walls to be 5cm thick.

Is there any solution for this? Thank you.

This is more due to Frustrum Culling rather than Lumen.

Try manually increasing the bounds of each placed wall, or try to use the command r.HZBOcclusion 1 and see if that helps!

What do you mean by increasing the bounds?

I tried the command and it helped little bit, now the black glitch is not that visible but still there.

I also found that is not just black glitch, the colour depends on the background, if I use Sky Atmosphere or just unlit sphere in some colour the glitch has that colour.

Are you using HISM(hierarchical instanced static meshes) for walls?

I found that problem is probably in my walls, because there is no problem with standard cube, but only if the wall is really thick (50+ cm).

But I don´t know what is wrong in my walls, I made them from cube in blender, only modified them to overlap inside, because I had these black artefacts before if I made them without overlap. And also I would prefer make walls around 10-15cm thick, because otherwise it will not work for what I want.

I probably start again, but I´m not sure what is wrong.

Finally this helped me, problem was occlusion culling. I change the bounds like you said and it is working great, I also remodeled all walls thicker.

I found old video where is the solution and now finally everything working. Thank you so much.

Here is the video with solution