I went through a resist Dark Urge playthrough and romanced Shadowheart. Up to act 3 it seemed fine, I got the special romance related Dark Urge cutscene at the end of act 2. After going into act 3 however the game seemed to forget I was in romance. All of her responses were just generic non-romance responses to Dark Urge related events, with some of them being far from appropriate for a 100 approval romance situation. Now I find out there's supposed to be romance specific dialogue for Dark Urge during the bigger events and I can't seem to trigger them.
Some of her replies, in general, are pretty generic right at the start of Act 3 because of what choice she makes at the end of Act 2 if you
persuaded her to save Nightsong. Once she does this and talks to Aylin at camp, realizes she was meant to be a Selunite, and goes through the hair color image change
Until that point and a tiny bit after that, everything is almost like it resets with her. Not sure if this is the path you took, but that could be the reason. Or, knowing how much patch 3 borked romance in general, it might be bugged.
