OnePlus provides official rollback packages packaged as .zip files. You must download the specific firmware that matches your phone's regional variant. OnePlus 9 OxygenOS 11 Rollback Package Europe (EU): OnePlus 9 OxygenOS 11 Rollback Package North America (NA): OnePlus 9 OxygenOS 11 Rollback Package
Read the warning prompt detailing data loss, click , and select Install Now . Method B: If you are running Android 13 downgrade oneplus 9 to android 11 exclusive
. Your device will boot into recovery, perform a factory reset, and then start up running OxygenOS 11. Troubleshooting & Tips Regional Errors OnePlus provides official rollback packages packaged as