InXile Entertainment posted a tweet about the enemy movement bug, and that it will fixed in the next patch that gets released. Here is the question, and their answer.
More information.rangerkeenan Any news on when the enemy movement bug might be fixed? It's unfortunately making me hold off from buying the game!
StigAlder yeah, that one sucks. It's already fixed in code so it will be in the next update. Targeting end of next week.