I’m busy today so I only skimmed responses, but it looks like indeed some logic was attached to the third person character or character controller actors that are spawned into the level?
Take a look at the World Settings menu - that controls which actors get spawned by default. I dont know enough about unreal to say exactly why, but basically these default classes will be created when starting the game, and usually you’d override them with your own but if you haven’t touched them then the defaults will be present.
As mentioned earlier, for a widget to be appearing on the screen that means somewhere it is explicitly told to do so with a Create Widget and then an Add to Viewport node (assuming you are using blueprints.)
In addition to the blueprint search function, be aware of that little binocular icon on the search field. That will search through ALL blueprints.