Hi Andee,
Its hard to think that you did anything wrong. It seems that CODAP is confused. There is often a correspondence between file name and document name in CODAP, but it they are not always 100% in synch. Document name is the name presented in the field on the top left of the CODAP screen. I am having difficulty replicating what you are reporting. When you say you saved the file did you save it to your local file system or to Google Drive, and were you on a Mac or PC?
Thanks,
Jonathan Sandoe