It is not uncommon that teams disagree. In this article I'm not going to talk about how to avoid these situations, instead, I'll focus on how to proceed once a discussion has reached a deadlock.
Focus on decisions, not on discussions
Discussions can go on and on until a person gives up. This is not what you generally want to happen. You should rather turn the never-ending discussion into a decision to be made, with a number of options to choose from.
Understand where they stand
Ask your team members to add arguments for the different options. But also ask them how important the arguments are. Collective decision making is about gathering opinions and views.
Suggest a decision
It needs to boil down to a decision. So go ahead and suggest one. Then go back to your team and tell them what you suggest, and the rationale for it. You will be amazed how easily your team will accept your decision. And for a single and simple reason. You have listened to them! Their opinions are taken into account, even though the outcome is not exactly what they hoped for.
What if it backfires?
Of course, there is a chance for failure. Someone really doesn't like your decision. Then ask that person, is it something I have missed or do we value a certain argument differently? Once you have identified the difference in reasoning, make it explicit. e.g. "I think I value smaller and faster releases very high, while you see a value in major releases for PR purposes." And then go ahead with your decision.
Remember, collective decision making is about gathering opinions and views and not about unanimous decisions. The final say can still be up to a single child. A consensus is not needed!