I finished episode 4 and when I go to chapter 5, the flashback of episode 4 shows me making different choices. The group came with me to search for Vernon at the end of episode 4, but when I started 5, I was alone. There were several other things that were different.
I don't have a prefs.prop file in the steam folder. There is one in My Documents > Telltale Games > The Walking Dead.
I've replayed it many times and nothing I've tried has worked.
I ran the support tool and the file is attached.