Blank window when creating a OneNote tab in Teams

We have an interesting issue here - when you try to create a OneNote tab in Teams, normally it would sign-in/authenticate automatically then display a list of notebooks or give the option to create a new one. Now though, we are just getting a blank window with no option to select a workbook. All users seem to be affected, so it may be something tenant-wide rather than client-side, just wondering if anyone else is experiencing this?