OneNote Broken In MS Teams Channels

In the last week, when I go to either existing OneNote tabs or try and create one, this is the result:

Before it lands there, it briefly shows the content, which is still accessible/editable in the desktop app.  There is no way anymore to access or create pages or do anything other than open in app or browser.  It does retain the title.  Nothing can be edited or created in any Teams OneNote tab in any channel.