If you encounter a situation where your cPanel File Manager is showing another account's directory in the navigation pane, it might have something to do with the Settings.
It may look something like this:
When this happens, you may end up not being able to access your account's files.
The cPanel development team is aware of the issue and currently investigating it.
In the meantime, please follow this workaround to get it resolved.
Click the "Settings" button in the upper right corner of the FileManager.
Select a default directory (in this case, we have selected our public_html) and save.
