Mysterious difference in blackboard float value

I have a blackboard float value called Awareness.
When it is updated it behaves very strange.

In the attached pictures I print the value that is sent to the blackboard, and then print the value in the blackboard variable. And they are different.
Why do these two printout values differ???


Okay I think I know what’s going on. Earlier in the function the Awareness variable is referenced and that reference is updated as well, which causes the increment to be added twice.