Are you in control of your story?
In The Hobbit, Tolkien observed that "things that are good to have and days that are good to spend are soon told about, and not much to listen to; while things that are uncomfortable, palpitating, and even gruesome, may make a good tale, and take a deal of telling anyway."
In other words, if there is no conflict, there is no story. So the characters can expect to have problems which get ever more difficult, they must face their fears and see their ambitions endlessly thwarted. No wonder they sometimes shut off and refuse to act as the author wishes.
Writers all experience the phenomenon of a character taking over the story and dictating what he or she will do and most certainly will not do. It takes time, a lot of thought and some bargaining between author and characters, to get things moving again. The revised plot rings truer and is more satisfying for all concerned.
So an argument with the characters is a sign that they are ready to walk off the page; and as every writer knows, that is the best thing that can happen in any story.
[ Photo of my workbook for The Rake's Challenge. There are four rakes in that tale,
two of them brothers. ]