As the device is being managed by Intune, by default it will try and sign into Teams with your @medschool email address rather than your @cam address. You will then receive a message stating "You're missing out! Ask your admin to enable Microsoft Teams for the Clinical School Computing Service":
Click on the "Use a different account" button
You should now be taken to a Teams login page (if it seems to freeze on signing you out, just close and re-open Teams):
At the login page enter your @cam.ac.uk email address, and click Next.
You should now be taken to the Cambridge University branded login page - enter your Raven password and click "Sign in":
When prompted to "Stay signed in to all your apps" click "No, sign in to this app only":
Teams should now sign in with your @cam.ac.uk email address.