iCloud drive complete reset

My iCloud Drive sync is not working on any of my devices (MacBook, iPhone and iPad). When I add files to drive on any device, they are not uploaded.  

It is only iCloud Drive (files and folders) and books— syncing of photos, notes, contacts, passwords etc are all unaffected.

I have tried everything including the following: 

(1) Full factory resets and clean installs of all devices

(2) Deleting all files from iCloud and starting over

I have also excluded it is network-based issue, as my devices and MacBook running through a different iCloud account are all syncing fine.

Is there any way to reset my iCloud Drive so I can start from scratch? It seems to be a problem with a corrupt hidden file on iCloud.