https://wccftech.com/google-urges-oems-support-rollback-protection/

With the advent of Android 8.0 Oreo, we have seen Google getting more serious about security issues on Android devices. The company has introduced numerous security features with Oreo such as Play Protect and a new security feature dubbed Rollback Protection.

This feature is pretty crucial for ensuring the safety of the device from hackers who often downgrade the Android version without user permission. Rollback Protection detects if a device has been downgraded to the previous version of the operating system. Unfortunately, it is not on every device that runs Oreo.