Randomisation on distinct events

Hi.
I have an event that has a probability of 50%.
That event is being spawned on many different emitters in game.
But they all stick to the same 50% so to speak. That means that once random probability of 50% has been met, they all play at the same time or they are all quiet at the same time.
I want true random behavior per local instance. Not per global instance if that makes sense.
How can I achieve this from the same event?

Thanks

When I test here, each instance of an event checks its instruments’ probability trigger conditions separately and independently of earlier instances; if I play multiple instances of the same event, each containing an instrument with a 50% chance of playing, approximately half of them will play. This is the expected behavior, and can be readily demonstrated by creating a new scene in the sandbox window and dragging instances of the event into that scene one at a time.

I must be doing something differently to you. How exactly are you triggering instances of the event in your game? If you try dragging event instances into a sandbox scene as I described above, does the issue still reproduce? Are you able to post a screenshot showing the probability trigger condition of the relevant instrument?