Whenever anything bad happens in one of these stories, or whenever anyone does anything seemingly stupid or thoughtless; the readers always blame lack of communication. I agree with them, the vast majority of their problems would be solved if the characters just talked to each other. With all their problems resolved the characters would all be happy, we'd get our happy ending and the story would end. Or there would be no story to begin with. That's not the point of a story.
A lot of readers seem to assume that they would never make those mistakes, that they'd be so much smarter. These are characters with different personalities and varying backgrounds. Dunoa, the MC, is reincarnated, she is predisposed to not telling people certain things because they would not believe her. Alice has prophetic dreams that she has 100% faith in despite the fact that they haven't all come true. Thus she believes that since Nocton did bad things in those dreams, he is 100% a villain with nothing more than purely evil motivations. Nocton grew up isolated and scorned by EVERYONE besides Dunoa. No one ever took him seriously until he took away their choice to. Communicating is something he doesn't quite understand because no one has tried with him. Even Dunoa just let him test her and never said anything about how she felt about it until now.
It's because these characters are who they are that they aren't going to explain and fix the problem quickly. It makes them, shockingly, good characters.