When uploading a folder via web, when prompted with regard to what to do when a file already exists, if you choose skip existing files, those files are then listed in the Failed list, as Canceled.

This can be confusing, because if you have files that actually failed, instead of being skipped as intended, then you cannot distinguish those from the ones you've said to skip.

I'd expect skipped files to show in Completed, or maybe some other tab, rather than Failed.