Problem in changing slider value by another blueprint

i have a slider in my UI and want to change camera zoom value , its working when i change slider directly on ui , but i want to change that value sometimes by another blueprint , slider on ui changed but its not update zoom value , i have a OnChangeValue event for changing camera zoom.

here is my HUD Blueprint :


and here is that blueprint for changing value :


the problem is onchangevalue event cant update if you change the slider value by another blueprint , so i set my zoom value in the custom event and now its work