I wanted to really love this flick. It started out really strong and the music was awesome. However the story was lost once the vampire scenes came into play. Instead of weaving vampires into the story and using it to heighten the story, it became the story.
The really weird thing I noticed that the aspect ratio changes back and forth in the production.
I had a similar reaction. The first half hooked me because it spent time building the characters and atmosphere, then the horror elements took over so quickly that it felt like two different movies. I didn't mind the vampire concept itself, but I wish it had stayed more grounded in the themes that were established early on.
As for the aspect ratio, that was an intentional creative choice. The film switches between different formats during certain scenes, so if you're watching the 4K disc and the image keeps expanding and shrinking, it's not an issue with your TV or player. Whether people like that approach is another question, but it's definitely something you notice while watching.