After deleting a notebook on onedrive.com, why does this notebook name still shown in the list of more notebooks in OneNote client?
How can I completely remove these deleted notebooks?
You need to empty the list of "Recent" in traditional Office OneNote (for example, OneNote 2016) in Windows systems.
The OneNote client of other platforms's "More Notebooks" window will no longer lists the notebooks that have been deleted from onedrive.com.
Don't know why OneNote 2016 's "Recent" list affects "More Notebooks" of other platforms OneNote,
In Windows Office OneNote 2016:
Click "File" tab -> "Open" page -> "Open from other locations" -> "Recent", the recent notebooks will list on the right.
Right click on a notebook, click "Remove from list" menu item. And do this again to remove one by one notebook from recent list.
After you empty the recently used notebooks list, when syncs to OneNote on another platform, you can see that the notebooks have disappeared from the more notebooks list.
If you emptied the Recent list in OneNote 2016, the existing notebooks will also disappear from the more notebooks list. But, you can wait patiently，and they will return.
Or, if you can reopen a notebook in OneNote 2016, the "More Notebooks" list on other platforms will restore the existing notebooks.