Manage Team Not Showing All Team Members

I have faculty members reporting that students are being removed from Teams randomly because they are not showing up in the UI when the instructors check the Team membership.  

When I look at the Manage Teams area of the Admin portal, all of the students are listed, even though they are not showing up as members of the team in the desktop client and the web app.  I've had to remove the students and re-add them for them to show up in the UI.  Has anyone else run into this?