Why unloading sublevels does not free / release memory?

We are using one empty persistent level and multiple sublevels.

Those sublevels are loaded and unloaded through blueprints in event track in the sequencer.

When we play, the sequencer is automatically played.

The question is here: Only one level is loaded at the front of the sequencer like below picture.

However, as you can see, ‘Texture Memory Used’ is almost 5GB while the loaded level’s texture costs 400MB.

5GB of texture is the sum of every levels’ textures.

I wonder why.

Thank you.

I think you’ll find that when you try this in a production game, it does work properly. Just not in the editor version.