"Use Controller Rotation" yaw/pitch/roll checkboxes question

I have been following tutorials and now I have made 2 different FPS-type projects

in the first picture, I have set up a basic WASD and mouselook control scheme, and it doesn’t matter if any of the ‘Use Controller Rotation’ checkboxes are checked, the mouselook still works

in the second picture, mouselook isn’t working because the ‘Use Controller Rotation’ yaw and pitch checkboxes are unchecked, they need to be checked for mouselook to work

why is this?