Wheel Bearings coming loose
Well keep your head on square. As I said before, these are simple. There's only so much in there. But you do have to use your head. The guys on here have pointed out just about any possible trouble.
One last thing. Seal interference. Maybe something wrong there, holding the entire assembly out away from allowing the rear bearing cone from seating properly on the spindle shoulder.
You should be turning the hub by hand, tightening the nut "with some force." Just a pull on the wrench with one hand. The hub will get harder to turn but should never get difficult. Then loosen the nut and reset for proper running tension.
As I "headed towards" earlier, given that you are having this type of problem, and this is a SERIOUS problem, I would be tearing the hub completely apart, cleaning it down to "bare solvent" and giving it a CLOSE inspection, and along with what was posted earlier,...........
take the cones and TRY fit them on the spindle. Do they fit on their relative positions? Does the rear cone seat on the spindle? Etc?