This problem (and the general problem with conversations in the movie) are I suspect the result of conversations being edited down too much. If so, the characters aren’t really having a natural conversation–they’re responding to things that have been cut or moved. The emotional and expressive performances out of sync, and that lack of tension would be a symptom.
I have a general suspicion that the movie was a lot longer, too, with a lot more character drama, but Villeneuve was made to (or decided to) cut it all out because of how important it was that this movie register as an action blockbuster.
