I think before you should have just brought the treee in from
the outside you should have slowly started to wean it from
direct outside sun light and you should have stated to put in
shade. Even though it is in a south window it is not the same as being outdoors in direct light. I don,t think i would keep moving it around. The tree should stop loosing some leaves once it gets use to being indoors. The object is to find that fine line when to bring in your tree,s from outdoors. I have gone to a grow light systems in my house. It has worked out just fine, i almost loose no leaves and can get my tree, sto flower even through the winter here in New England. You also
want to keep and eye on your tree for Insects. Fukien Teas and Insects are like Dogs and fleas they just go together. Just keep and eye on them and you should be fine. If you need to e-mail me feel free to post . Hope this help,s
Good luck