A knowledge base article about Help! DUO says that my account has been locked! provided by the UC Berkeley IT Service Hub - Knowledge Portal
Users can accidentally lock themselves out of DUO if they make a certain number of failed authentication attempts. In these cases, the user should wait 5 minutes and then try again. After the wait time, the user should be able to re-authenticate without error.
If this happens repeatedly or the user still receives an error after the waiting period, then the user should contact 2-Step support at calnet2-stephelp@berkeley.edu