Mode 2d can sometimes make texts inside buttons positioned strangely, even though they are all anchored correctly. That doesn't occur with mode Viewport, but then everything is slightly blurry. No matter the aspect I choose (keep, expand, keep height, keep width), it will not fill up the width of my screen. I can choose the ignore aspect, and it will skew it and always fill the screen, but it won't maintain any aspect ratio and obviously that's not the answer lol.
I'm content with keep, as it fills the height of my screen, and it centers it horizontally. Thanks, lads