How do I get my team to stop avoiding conflict and say what they really think?

A team that is always pleasant is not always healthy. When everyone stays agreeable on the surface, the real disagreements do not disappear. They go underground. And the things you never talk about are usually the things quietly deciding how the work actually goes. The harmony you see is a kind of performance, and part of you already knows it. That is uncomfortable, but it is useful. It means the problem is not that your people lack opinions. It is that they have not felt it was safe or worthwhile to say them out loud. Politeness became the cost of getting along. You change this by making one disagreement safe. In your next meeting, ask a real question and then wait. Invite the objection nobody has said. When someone finally pushes back, thank them out loud, even if they are right about something uncomfortable. People say hard things when they see that hard things are welcome.