Support has confirmed that an Address record will not be updated under certain conditions.

AUX_ADD_LINE_1 works for uploading Apartment numbers (i.e. Apt 100), but not for other types of data.

AUX_ADD_LINE_2 does not load any data at all unless the database is running TA v5.0.19, which includes AF 2409806.

Options:
There are other extra line fields that are working so you can get your data file or control file modified to upload to a different extra line field. Team Approach Support can assist you.