Overlay appearing and disappearing with condition

I'm making a mod where there is a blood moon event (GLOBAL_WORLD, logic type, default value: false) and i want an overlay to appear on screen whenever this event happens.

here is the condition i made :

https://imgur.com/a/pYJCvgg

now when the blood moon initiates the overlay does appear but only for a frame before disappearing again (i have an item that tells me if the blood moon is happening and it is still happening when the overlay disapears)