OneNote Syncing Issue, Error Code E401064C

Hello ... We have an intermittent problem with OneNote file syncing. We have several OneNote notebooks stored in SharePoint.  About 3~4 times a week, all of our Notebooks will stop syncing with the error code 0xE401064C.To fix the problem we perform an iisreset on the SharePoint server and all the notebooks then sync again. But we cannot find the root cause to permanently address the issue and our end users are now getting frustrated.

Is there any insight on how to fix the root cause (i.e. patches, configuration, etc.)?

Thank You!