A binding is similar to running something off tick. It continuously performs the function in the binding and outputs the data accordingly updating whatever it is bound to. What I am saying is, instead of doing this as a binding, manually create a function within your widget and call it on event begin play. That way you can control the number of times it runs. It will run once on begin play and then never again unless you call it a second time. I have this setup in my own game and it works perfectly. See screen shots below.
