Nate: Be sure the bearings have been greased. My neighbor bought a "similiar" style trailer from a fairly popular area lumber yard (the name begins with an "M")

and he lost a wheel (axle spindle wore right off) about 2 months later. Turned out, both bearings were dry...never had any grease
properly applied to them. He said there was a "lump" of grease on the inside wall of the hub, but the hub wasn't fully greased and the bearings themselves were dry.
All he lost was the axle/wheel combination. No one got hurt. He trashed the trailer. It wasn't worth the hassle to find an axle and go through the grief to bring the thing back to life. His words: "It didn't cost that much. I should have checked the bearings. My fault."
But, wouldn't
you have thought that all was up to "spec" when you bought it? It maybe does pay to double-check everything, and not assume all is as it should be.
Good luck!