You might have to check for updates, " Unless noted, software updates provided on this page are exclusively for retail and online purchased versions only. To check for updates for hardware bundled versions, locate the "About" dialog in the software, and then click on the "Upgrade" button. In the Upgrade dialog click the "Update" tab to see if there are any updates available. Also note that the software will pop up a notification periodically when there is an update available." From here.
Xiaomi Mi Mix 2 review