Hello @Bailey and welcome to the forum!
Is that implying an increase from a smaller backup? If so, how did the smaller one go in terms of seeing files show up? Did you earlier see the folder made by Duplicati, e.g. when using destination’s “Test connection”? Google Drive has some interesting security features, and default Duplicati usage (which can be changed) is that Duplicati can only access (including seeing) folders/files it made itself, however all can be seen by you.
The huge size oddity might be worth tracking down. I would hate for Duplicati to try to backup 129 real TB… Does your file manager have the ability to report a size on a per-folder bassis? If so, that can help trace this. Files can be seen as larger than the space they occupy. Sparse file describes this. From the command line, you could also try du with “-apparent-size” to see if you can track down the huge files. Maybe you’re at one?
You might be able to get a view of what’s happening by opening a browser tab to MENU --> About --> Show log --> Live --> Profiling (or lower – Information is good). Logging varies by Duplicati version. What’s yours?