I’m on momento mile trying to get it to 5 stars and the only objective I’ve got left to do ii get the enlightenment to level 23 but it seems to be stuck on level 21, I’ve been analysing prehistory things for the last  4 hours and it hasn’t even gone up one? Hoping some can help please before I lose my mind? 

Enlightenment only increases if your knowledge does. You need to find new exhibits to analyse, ones that you haven’t maxed the knowledge on yet.