Gdetrailes, stated. "Trailer axle bearings are not "factory sealed permanent bearings" which have no adjustments.. They are indeed "adjustable" and as they wear, they should be checked and adjusted as needed. As they are adjustable, it IS possible that they may have left the factory a bit on the loose side (not correct preload) and OP has put 10K miles on the trailer meaning it may be due to check and adjust the bearing preload."
If a properly adjusted tapered bearing has become loose, is should not be readjusted, as there will be metal missing from the bearing, making it non serviceable.
Richard