I have this issue too. I used this tutorial to make a smooth scrolling camera.
As the camera "settles" on the player when you stop moving, it will jitter 1px to the right, then 1px to the left, then stop on the character. My "resolution" is set to 256x144 and my tiles are all 16x16, so single pixels are noticeable. It's most notable when there is a foreground scrolling parallax layer. I probably gotta tweak the lerp settings, but I thought I'd mention this regardless.