So, the things I found wrong with it:
Alessandra de Rossi is good, but she seems too old for the youngish guy in the Marinduque scenes, and in addition to that, an absolute cold blooded B in the way she left him after he and his sister extended so much hospitality to her. Sure we’re supposed to feel empathy towards a woman desperate to resolve the mysterious postcards she’s been getting, but when there was apparently no scene of her giving the guy an explanation or even a goodbye I felt sorry for the him.
About those postcards, it took up to the start of the second act for me to realize those cards were mysterious at all. I thought they were still from her ex but it wasn’t made clear it wasn’t until way into the movie. Which is a pity because the plot was fairly rich. It wouldn’t have taken a sentence or two to establish this, perhaps by declaring this before she went on her trip.