I have set up a Class Notebook for a Team through Microsoft Teams. I recently distributed a new page to all members of the team and pushed it through the Teams app. It is not appearing in the Notebooks of some of the members (seemingly random where it does / doesn't appear) when I access things through Microsoft Teams App, however, when I access the same Notebook through the One Note for Windows App, the document is showing (see the two attachments).
The document was sent over 24 hours ago and we have managed to make sure that both Apps and the Notebooks have been synced / reloaded several times.
I have found a way of making sure it appears in Teams, which is to go into the affected Notebook section, hit "Add new Page" and this somehow forces the 'missing' document to appear. But it is a very time consuming solution when you are looking at sharing documents to maybe over 200 people a day!
Likewise, maybe you might suggest just using One Note and ignoring Teams - but again, that removes a lot of the convenience of having everything in one place (Teams) - when you are communicating frequently with several different Teams as well as individuals via Phone/Chat and needing regular use of the Calendar function!