Alternatives to full downgrade
Once the installation finishes, your phone will prompt you to . It will boot into recovery mode, perform a factory reset, and then restart into the OxygenOS 11 setup screen. Alternative: The MSM Download Tool Downgrade Oneplus 9 To Android 11
Once downloaded, move the rollback ZIP file from your "Downloads" folder to the root directory of your phone's internal storage (not inside any folders). If the file ends in or has extra characters, rename it to end simply in Initiate the Rollback: OnePlus Local Update app you installed. Settings (gear) icon in the top-right corner. If the file ends in or has extra
To downgrade your OnePlus 9 to Android 11 (OxygenOS 11), you must use a official . This process will completely wipe all data on your device, so a full backup is mandatory before starting. Prerequisites This process will completely wipe all data on