How do you guys go no contact with kids involved?

My ex wants to be friends but I’ve made it very clear that I cannot do that. She knows that I only want contact to talk about our divorce progress and the needs of our kids. But she has been persistent with forcing small talk about her day/week when we do have to see each other. It’s crazy that she can think that all is well when she’s in a new relationship and can be chill with talking to me as if nothing has happened -_-