I tested every dither type and ONLY kDitherTypeBayer4x4 has this issue. Not even 2x2 or 8x8.
The image returned from blendWithImage is offset 1 pixel to the left.
(FWIW I did not set the phase manually.)
My full code (blending two 400x420 images):
newTimeImage:blendWithImage(oldTimeImage, transitionAnimator:currentValue(), gfx.image.kDitherTypeBayer4x4):draw(0, 0)
I have to set that to draw(1, 0) if I use that specific dither.