Can't control Widget with Controller inside Editor in C++ Project

Controlling a widget with a controller is not working inside the editor, but only in the build.
I did a few tests with fresh UE4 projects and found that this issue doesn’t happen with blueprint projects but only with C++ projects.
When I create a fresh blueprint project, I can control widgets with my controller, but when I create a fresh c++ project, it suddenly stops working inside the editor. It still works on builds but inside the editor, it just refuses to work.
I really don’t understand why this is happening.

Has anyone ever encountered something like this?