A common reason Duo accounts lock out has to do with how Duo notification settings interact with an application's syncing settings. If a Duo account's device settings are set to "automatically send this device a push," the connected device will receive a push notification every time an application syncs. This can often cause many push notification time-outs and result in an account lockout.
To resolve this issue:
1. Visit duo.davidson.edu.
2. From the "Do You Duo?" page, in the lower-right of the page, select the green "Manage Devices" button.
3. Select "Send me a push" from the left-side prompt
4. Accept the push notification to get to the next screen
5. Under "My Settings and Devices", scroll down to "Default Device"
6. Click the drop-down arrow next to "When I log in:"
7. Select "Ask me to choose an authentication method"
8. Click "Save"