There is an error in the sync log:
E080
Description: An error happened on the task '...'
solution: Please recreate it or contact us.
When I go to that task, it actually won't let me edit or delete it, so I can't do anything about this error.
The other tasks still seem to sync ok.
Hello,
It may be brought from the old version.
We've attempted this issue in 3.9.6. http://enblog.doit.im/post/49909570183/doit-im-for-ios-3-9-6-release-notes
Please make sure that all other tasks has been successfully synced and then log out of the app and relog into it to have a try.
Sorry for any inconvenience.