BSP Issue when placing Brush

Just a bit of Help really, I’m a total newbie when it comes to Game Design engines etc etc and am learning via YouTube and other videos :slight_smile:

Could some tell me why UE4 does this weird culling thing when placing BSP’s inside others when blocking out a map for example?

This only seems to happen with “solid” BPS’s when I changhe to “Semi-solid” the issue seems to go away.

Any help / info greatly appreciated :slight_smile: