I was recently writing a story and while having a character interact with a different character the dialogue indicated that they were not going to do what I intended and instead charted a different better course. I don't want to say that I changed their course because it was thinking about what they would say that made me realize my choice for them wasn't right. It wasn't until I was working on their side of the dialogue that I realized that my path didn't make sense and the words that would lead them to that path wouldn't make sense for the character.
Yes yes yes. I am having that happen to me right now. One character has a full story arc and while interacting with another character, just will not come ito the plot for the story. I'm having him sit in the wings till he comes forward ;-)
Brandon Sanderson has a video where he talks about plotters vs pantsers and he says that for him, he plots the overall story, but when it comes to characters, he doesn't.
My characters have a tendency to move in different directions than what I originally planned. Its frustrating and annoying that they won't do what I plotted out. The pain is real.