Our teams are aware of this issue and are still investigating and looking to collect more information about it. If you would like to contribute to this investigation, please navigate to Help > Report a Problem. Please be advised that you won't receive any direct updates on the issue, however, the information submitted through Report a Problem is received and reviewed by our development teams.
In the meantime, I suggest that you restore a backup that was saved prior to this issue occurring and turn off mobile sync to see if that may help.
Once you've restored the backup, please follow the instructions provided below.
Make sure to sign up for the email digest to see a round up of your top posts.