Blueprints - isFalling doesnt seem to flag up when in air?

So I’m working on my Fall damage for my character and it use to be working just fine but now I cant seem to get the isFalling bool to become true no matter how high I jump nor how high i fall from. I am using the isFalling to start a falling timer to calculate if the character has been falling long enough to warrant fall damage but as I cant get the isFalling to flag up true I cant get it to work properly.

I have attached a screen shot of the relevant blueprints

I thank you for you time all of you.