Do not have permissions to edit a new notebook in my own OneDrive?

As per the title, I cannot seem to edit a brand new notebook in my own OneDrive for Business.    Here's the breakdown of what's happening:

• Shared a folder with a colleague (w/ edit permissions) from my OneDrive
• Created the notebook in said folder
• Created a section and was then promptly locked from making any further edits to the notebook
• Colleague cannot edit either.  Tried giving them "direct access" but that setting doesn't stick because the folder properties seem to override them
• Colleague created their own notebook in my shared folder;  they can edit but I cannot.
• OneNote web app keeps saying that I don't have permissions to edit either notebook (despite being the owner of the folder and creator of one of the notebooks)
• Tested same process in my test tenant and that worked just fine.
• I can open and edit other files in the folder just fine.  This issue seems to be limited to OneNote and my account
• Logged out of O365, closed the browser and logged back in, but no change.

Anyone have thoughts?  We are completely dumbfounded why we can't collaborate on shared notebooks.