How to keep an async loaded Level in memory after set should be loaded to false

I used Asset Manager to list levels as primary assets to async load and I have some volumes to load and visible levels.

after I async load levels stat levels shows in memory levels in blue and on begin overlap of visibility volumes I set should be loaded and should be visible to true then stat levels shows visible levels in yellow and on end overlap of visibility volumes I set should be loaded and should be visible to false then stat levels becomes red for those levels but I wanna keep them in memory