Resolved - Duo MFA Reports Some Issues with Phone Callback

Update: Duo announced that there are no longer issues with phone callbacks.

Duo, used for multi-factor authentication (MFA) for CUIMC VPN and Columbia web applications, is investigating reports by some users with phone callback via Duo.  For immediate updates please see the Duo status page at: https://status.duo.com

There are not widespread reports of the issue at CUIMC.  If possible, you can use an alternative authentication methods such as Duo push, passcodes, or SMS passcodes.