OneDrive not syncing properly
I have this problem too. Open a Word document on OneDrive using Hancom Office, for example,  edit and save it.

The document is saved in a cache on my tablet (labelled onedrive) but never updated elsewhere. The only way to update is to "save as" somewhere you can find it an reshare from the tablet manually.

This makes it a half useful app on tablets. Works fine'ish between PCs