i somehow missed this thread, are you sleeping (not resting) in your room at the tavern? From my guide:
"For the last part of the war, you just need to have completed part 4, check both tribes and then go to sleep in your room and the game will ask you if you are ready; this part also requires you to be at least on day 35 (or day 40 if you haven’t completed “saving the master”)."