I have this issue on one of my accounts, for some notebooks in that tenancy but not my corporate "personal" notebook. The personal notebook opens fine in OneNote UWP (Win 10) version. The notebooks in my SharePoint sites open in web, but not in OneNote UWP. They open fine in OneNote 2016; my conclusion is that there is something wrong with that account in my OneNote UWP, or OneNote UWP itself. I have yet to figure out what I should do moving forward, since I don't want to use OneNote 2016 (I know the day will come when support for OneNote 2016 will end).

Have you tried re-installing OneNote (I can see that you are on macOS). I may try that step next.