I followed your suggestion, I updated the lives in my GameInstance within my Killbox, and then I added an EventDispatcher and called it in the HUD.
By the way, I also tried using Bind from the HUD, and it worked, but I found that Bind operates similarly to the Tick event, so I decided not to pursue that route.
Here’s a quick video demonstrating it in action.
https://youtu.be/uYsAhDj6Hb8