Hi Victor,
This is due variances in the plastic lens that covers the LED beneath the pixel. It’s bending light slightly differently than the other pixels. There is no fix for it besides replacing the LED, which requires dismantling the Game Frame. Your particular case is on the edge of what I’d consider permissible in the QA process. That said, I’m happy to exchange the LED panel if you want to return the Game Frame. Just send me an email to jeremy at this domain and let me know what you want to do.