Hello DetHlyOmen, let me help you with this. When using the Landscape Brush Manager with World Partition, it creates persistent dependencies on the landscape, which prevents World Partition from properly unloading cells. As a result, the entire world is loaded into memory, even on non-source builds.
I recommend either removing the Brush Manager or disabling the “Affect Heightmap” option in its settings. While this solution isn’t perfect, it allows World Partition to manage memory correctly.
Currently, there is no straightforward fix for non-source builds. While custom brush systems may help, they require more complex setup.
I recommend that you read this topic.
World Partition Doc: