Asked to describe a conflict with a coworker and realised I don't actually have one

Every behavioural guide says have a conflict story ready. I've been working three years and the honest answer is my disagreements have been things like picking a different library and moving on within the hour.

So I stretched something tiny into what it wasn't and I could hear myself inflating it while I talked. Interviewer moved on quickly.

Is the right move to just say the disagreements have been small and walk through how one got resolved? Or does that read as someone who dodges hard conversations?