The last Jedi has left a few unanswered questions. Kylo Ren seemed to perfectly recall himself waking up and Luke holding a GREEN lightsaber up at him (his lightsaber from RotJ). So when Luke and Ren were about to face off in TLJ he should’ve noticed the hilt was Luke’s original blue blade, The same one that him and Rey split in half. Now for those who say “well maybe he generally didn’t look at the hilt”, I perfectly recall him noticing it in the force awakens. It was the first thing he said when Finn pulled it out hence probably one of the first thing he looks at.
Another thing I sort of picked up on is, Maz has been alive to see the PT-OT-ST so I expect she would no who and how many people know how to break onto The Supremacy. So where did this guy in prison come from?