thought I had uploaded some
This is not helping. This, on its own, would, of course, work - clearly indicating that the issue lays elsewhere.
What is firing that event and when? How do you know the value is not set? Do you use the variable anywhere else? Is the widget on screen? How is it created? I could ask 100s of questions and list twice as many reasons as to why it may not work. It’s the same as saying, “Print String is not printing, why?”
Consider describing what you’re trying to do and how you’re approaching it.