My first question would be about a possibly counterfeit part (the axle?).
Next, I would wonder if there might have been a nosewheel strike (pothole, that sort of thing) or a hard landing overstressing the part.
Another consideration (and I'm completely guessing here) might there have been a bad pushback connection at some point.
Lots of potentials, but let's look at these before wandering into the weeds.