Another issue is improper welding that can have the axle actually SEPARATE from the trailer.
Pretty scary - just happened to me with a 2013 Camplite QBB 16ft trailer. If not at a stop, could have been killed or killed someone, plus destroyed the tow vehicle.
BEWARE - that's in my post too, you can read, see a link about another Camplite axle coming off on the road and see photos (do a search).
best, Molly