A sentence can be grammatically complete and emotionally unfinished.

A sentence can contain everything grammar requires and still leave the important part unsaid. I understand. It is fine. We will see. Complete, unobjectionable, and clearly not finished, and both people can feel the missing half sitting in the room afterwards.

When a reply feels closed but unresolved, the gap is usually where the real content is. You can name it gently, saying it sounds like there is more. And when you are the one giving the tidy incomplete answer, notice what you are choosing not to add, since the other person almost certainly noticed too.