How my e-reader lost its stripes

The author discovered vertical stripes appearing on their Xteink X3 e-reader when displaying greyscale images, which weren't present in the original bitmap files. After investigating with AI assistance, they learned that CrossPoint firmware renders greyscale by first drawing everything black, then using voltage pulses to move selected pixels toward white—and the stripes were caused by incomplete pixel updates during this second stage of the rendering process.