I am currently on Chapter 2 and just killed all the trolls in the swamp (and got new spells after getting a shard). A random number of turns after that I immediately jump to Chapter 5. I've tried reloading various saves but to no avail. Also, I have two cities in the campaign and sometimes the autosaves attaches the wrong city data to the wrong city (my older city has all the resources as buildings of the newer city and vice versa).