OneDrive is migrated with the option of "All items that were added or modified since the last migration", which would allow to skip enumeration, making the OneDrive migrations (especially at cutover) run way faster. However some OneDrive migrations are still enumerating everything in source and target and that is taking a very long time for the large OneDrives. In addition, this is causing throttling messages. What is the reason?
More than 5000 OneDrive objects in the scope, which is Microsoft API limitation.
When account's OneDrive is having more than 5000 objects (files+folders), Microsoft API will not return the list of changed objects and will re-enumerate everything in such case.
