Why does Duo ask if this is my device?
If you have a device that only you use, it may be helpful to skip the constant authentication requests. The first time you authenticate using Duo, you will be presented with an option to remember this device. Selecting "Yes, this is my device" will cause Duo to remember your authentication information for the browser session on your device for a short time period (generally 30 days for campus users).
NEVER select this option on a public access computer, such as a library or conference room computer. Doing so may give others Duo access to your account.
If you no longer want to trust your device, you can uncheck "Remember me" when authenticating. If you do not see this option, you may need to cancel the Duo authentication in progress, and then uncheck "Remember me" before trying again.