Photoshop for the iPad pixelated lines

Hello,

I exclusively use the iPad version of Photoshop. Whenever I draw on a smaller canvas, and I only use the hard round brush with use pressure for size selected (see attached picture below), like 500 pixels x 500 pixels, the lines are smooth and just fine. But when I draw on a canvas that's 2048 pixels x 2732 pixels, the size of my iPad screen, the lines are pixelated and don't look good. This has been an issue I've had since March or April, and it didn't happen the first week or two that I had the app. I've attached examples below. Thank you in advance for help.