Notebook "scrambled" in Win 10 but intact on iPhone

After trying to access OneNote from a different computer from my normal one a few days ago, the notebook content has been scrambled. A few sections are intact and some misplaced sections are visible, the bulk of the content has been lost though. I was surprised to find that the OneNote app on my iPhone is still displaying the full content, it had failed to sync one day last month and it has been working in offline mode ever since. There are two questions then, 1) is it possible to restore the original notebook content on the PC and 2) is there a way to restore the notebook from the iPhone content?

Thanks

Michael