Sometimes it's better to let a situation marinate a bit before you decide to try to find a solution.
As much as we like to tout our differences, when it comes to management we all exist on the same learning curve. I have had the same conversations about operations, personnel, and management ideas numerous times with all of my new managers over the last 15 years.
Why? Because no matter where I've worked there has been one constant: people. Whenever people are involved, the same issues will always exist.
Team development is always a topic. It takes a while to learn which team dynamics are healthy and which are toxic. One of my favorite conversations usually goes like this:
Manager: Team A is having all sorts of issues. They are infighting and not being productive at all. I don't know what to do to...
Me: Have they always been this dysfunctional or is this a new thing?
Manager: It's relatively new...been this way for a few days. I'm trying to figure out what I should do. Do you have any suggestions?
Me: I wouldn't do anything, yet. Let it marinate a bit longer before you insert yourself. If they were as productive as you said they were, they'll figure it out. A little conflict in a strong team isn't necessarily a bad thing.
Me: Yup. Give them a few more days or so and if it's still a thing come on back and we'll go over what to do next. Chances are good something has happened to change the power dynamic in the team...if so they'll need to work through it. In the interim, see if you can learn what is causing the argument.
Manager: Really? Okay, I'll see what I can find out. I hope you're right.
Learning when to do nothing is just as important as knowing when to act. Notice I asked about whether or not the team was "functional" before offering any advice.
Functioning teams are like many families. Teams will revisit the storming phase of team development from time-to-time. If you interfere before the warring parties have had a chance to reestablish their hierarchy, conflict will inevitably bubble up again.
If you aren't familiar with team development, check out this link.
Remember, not every problem is yours to solve and not every disagreement means your culture is deteriorating. Sometimes it's just a long, drawn out, uncomfortable series of conversations.
To paraphrase great warrior-poet Marshall Mathers:
"What's a little fight? Tomorrow you'll be boys again."