Thanks again everyone. When I prepared the FTM file to upload, I privatized it in the GEDCOM then uploaded it as a public tree. All of that worked fine. The issue arose when someone not marked living in my uploaded file was matched (via hint) with someone marked as living in someone else's file. I don't know how Ancestry manages to do that unless is matches parents, or dates, etc. Anyway, so I accept the new info into my online tree, the first name in my online tree is changed to living and the next time I sync to my local FTM file, this new "first name" replaces the actual first name in the local file.
So, since I did save a copy of the database before I uploaded it, and since I have only been updating via the online database for a few months, I pulled out the backup and as suggested by others, I did NOT privatize it at the GEDCOM phase and then I uploaded it as a private tree that I will send others permission to access. This is the only way I can think of to update my database without repeating the problem. This seems faster than trying to compare and correct the corrupted database.
Thanks again everyone. We live and learn, and, we never know what we do not know.