Hi, seems that you are previously loading table 'A', with the same fields as 'AA' (because the use of '*'), so it's autoconcatenating in table 'A', to avoid this you can use 'NoConcatenate':
If you keep all tables it will create a lot of syntethic keys (tables joined by more than one field), maybe you want something like:
LOAD * Resident B;
DROP Table B;
Or try renaming fields in 'AA' table to avoid unwanted keys.