I’ve created several KB articles for known Teams issues:

• MS Teams – Camera Not Working
• MS Teams – Notifications Not Working
• MS Teams – Email Notifications for Chat not Working
• MS Teams – How do I Chat with a Student Employee?
• MS Teams – How do I Chat with External Members or add Guests to a Team?
• MS Teams – My Pinned Items Keep Resetting
• MS Teams – Presence Information Not Displayed
• MS Teams – What is the Storage Limit in Teams?

Regarding the external members and guests, neither is working at this time. Please escalate such requests to the Office 365 tier 2 team. We will let people know what the status is, and keep them posted regarding changes.