Handling team conflict before it spreads
Two people not speaking is a problem. Three people picking sides is a crisis.
Get to it the same day
Conflict left to 'cool off' on its own almost never does. Same-day, short, in-person beats next-week, long, by email every time.
Hear both sides separately first
Five minutes each, on the side, before any joint conversation. People talk straighter when the other party isn't in the room.
Solve for the behavior, not the personality
You can change behavior. You can't redesign someone's personality. Agree on what each person will do differently next week, not on who is the 'right' kind of person.
Take your version of this question further
This is one operator-tested angle on the question. Your shop, your size, your trade, and your team change the answer. Ask your specific version inside Ask a Shop Owner to get a response grounded in how owners like you actually handled it.