Are you sure that the sealed cartridge unit is the proper size and thread pitch? If you were able to “back it out” you can check to verify proper thread pitch with the old drive side cup. See if the threads of the old cup seat perfectly in the threads of the cartridge bearing unit. As mentioned, the aluminum threads on the cartridge unit are the ones most likely damaged although there may be bits of aluminum left in the steel bottom bracket shell threading and definitely need to be cleaned out. IF the cartridge unit is, in fact, the right size, and the threads have been cross-threaded, it’s possible that your LBS may be able to “chase” the threads and save the day
.