Dropbox backup failure since June 2018

Dropbox backup has been failing for long time for me. I am on Frappe Cloud, is anyone else facing this issue ?

You can re-enter the dropbox keys and tokens and try to take backup again. Probably authorization failed at some point.

Backup is happening partially, it is failing midway with some uploaded file. Database seems to be backed up, it is the uploaded files and attachments that are failing.