Thanks for all the input, Bhelogan!
I tried to reproduce the Monk levelling problem, but they levelled up just like the other fighting classes. The only delayed level ups should be for Wizards and Archmages.
If you want to, you may send me your final savegame to info(at)gatesofintegrity.com so I can take a look into what happened.
Glad you enjoyed the game! It was a blast making it.