Over here https://answers.unrealengine.com/questions/259606/how-to-move-widget-with-gamepad-or-better-ideas.html a guy is suggesting to just use Rama’s plugin. Have you tried that?
EDIT: tried to install and it isn’t compatible with my version of the engine, could be the plugin is outdated or it could be because I’m on a mac. So back to the drawing board.