GameInstance work with simple bool, dont with array of actor

my gameinstance can keep the state of one simple bool variable through the differents levels of my game.

when the game start, i fill the array of actor, and i can work with a foreach loop, all is fine, no error. but when i change the level i cant foreach my array anymore because he is now empty when i try i have error “accessed none”

is that normal behavior due to an array of actor?

It is normal behavior. Actors were placed or spawned on the previous level and the engine during transition to new map cleaned them with references in your game instance.