A family of Microsoft products that enable users to capture, organize, and reuse notes electronically.
We are working on resolving this reported problem. I don't believe changing your device or resetting will help. For now, my suggestion is to restart the device when you hit either of the bugs since it clears out the root cause. You can also use the OneNote Win10 app which doesn't have the ink disappearing bug.
I will post here when we have a fix available.