I don't know if answers for this question could be useful, but let's try: Have you unlocked Northcrest and the acces to the munbury complex? What is your relationship with Logan and Ste? Have you compleed country road storyline and if so, good or bad ending? At night (around 20-24) can you talk to Ste about the hole in the fence? What is your mouth experience?
If you want you can save your game on page 12 or more and upload it on filebin.net so I can try to see what is wrong (if you're playing on windows).
BTW I suggest you to reply a new post that has the same problem for three reasons: other could have the answer, others could have the same question and the replies don't get buried (for example I read that you'd try to change role or position but only by chance I read your comment about still not be able to trigger it.