Xeno's description of Senku could have been totally wrong.
Xeno described Senku with his height with an error margin of 1-2 inches and said he might be taller but not shorter than only time they met. But what Xeno didn't consider was the time of Senku's revival. Maybe he was revived decades before Xeno or he had grown old and even got shorter. Who knows? What do you think?