@michael-divine, it can be modified through the .csv export file.
Go to Settings > FileBird > Import/Export, click Export and download the whole folder structure.
In the .csv, under “created_by” column, set all the values to 0. Save the file and import it.
It seems they define it as: 1 → first user (aka admin), 2 → second user, and so on. Number 0 → universal user.