Ford Focus 13 Passanger Light Short

I replaced my passenger low beam light because my car had that message pop up. So a few hours later the same message came on screen, and the bulb is out again.
I brought it into the dealership I got it from, they are saying that as long as it actually is the electrical system that shorted I’m covered but if not I pay out of pocket.
I’m trying to find out if I can figure out what’s wrong without having them plug it into diagnostics…?

Was the bulb out before you replaced it? If not, then the problem is somewhere else, and you need to either diagnose the problem yourself or pay someone to do it.

Much more likely to be an open than a short. Edit, on reconsideration, ignore this line.

I was looking forward to seeing 13 “passangers” in a Ford Focus. Seriously have you tried wiggling the bulb to see if it flickers or comes back on? That could indicate a faulty socket or connection which the dealership can correct under warranty.

When you installed the new bulb, did you handle it with your bare fingers?

If so, the oil in your skin gets deposited on the surface of the bulb. Then when you turn on the headlights that oil creates a hot spot on the bulb causing the bulb to burn out.

Tester

If you have an ohm meter you can easily check to see if there is a short or faulty ground. If you are interested we can go into further detail

As @tester said, The bulb will burn out if touched. Wear rubber gloves, or at least use a paper towel. Is the bulb really out?