Save collected items placed inside a streamed level

Hi all! Hoping to find a solution i’ll try to clarify what my problem is:

For optimization, my project is composed by multiples Sublevels of my Persistent Level.
They are loaded/unloaded in-game using Level Streaming Volumes placed in world.
Each sublevel contains a certain numbers of collectible items.
My problem is that each time a sublevel is unloaded and then re-loaded, every collectible item of that sublevel will “respawn” even if i have already collected them.
There is a way to prevent this? Or in other words to save how many items i have collected in that sublevel and then load only the ones i haven’t collected?

Thanks in advance to who will help me with solving this one!

Add a boolean on pickup, inside the game instance, i.e. Item1, Item2, Item3, and on spawning of each single item check with a branch if the Item is still false. Though there may be easier methods when you have hundreds of collectibles.

This is exactly my case…
I’ve read somewhere that this can be accomplished with a boolean array, someone could help me with this?

Anyway thanks for the advice!