You need to read the following information about how QuickBooks for Windows Sync Manager works, how to see if Sync ran correctly, if objects are in an errored state and how to resolve. It could be any number of things. Once a record is inserted into the cloud, it asynchronously downloads to QuickBooks on the desktop, at which time business logic is applied and records are matched from the cloud to the desktop. If there is an issue, sync manager will show a record of the object that failed, why it failed and the object will now be in an error state.
At this point you can review the error and take steps to fix, like revert or update and resubmit. Links to the documentation below.
QuickBooks Sync Manager
Data Sync
Objects in Errored State
Sync Activity
Sync Status
regards
Jarred