Tap or Upgrade . The phone will reboot into recovery mode and begin installing Android 11.
If you run into any specific issues during the installation, let me know:
Go back to the main Settings menu, navigate to , and confirm Developer Options is now visible. Step 3: Installing the Rollback Firmware
: Tap the gear icon (top right) and select the rollback package you moved to the root directory. Downgrade Oneplus 9 To Android 11
If you run into any specific error codes during installation, tell me your (found under About Phone, e.g., LE2115) and your current Android version , so I can provide the exact step-by-step fix. Share public link
For a clear, step-by-step process, refer to the OxygenOS Rollback Guide on the OnePlus Community .
Since the downgrade , use the OnePlus Switch app to back up your contacts, messages, call logs, and apps to an external USB drive or PC. Manually back up photos and documents to Google Drive or a computer. Tap or Upgrade
The for your specific region (IN, NA, or EU).
Once the OnePlus boot animation finishes, you will see the classic OxygenOS 11 welcome screen. Set up your device and restore your data backup. Step 5: Disable Automatic System Updates
Ensure your device has a battery charge level of at least 50% to 70% . A power failure during the flashing process can lead to a permanent brick. Step 3: Installing the Rollback Firmware : Tap
Select the rollback package, review the data wipe warning, and tap . Once the installation finishes, tap Reboot . Step 4: Initial Setup and Disabling Auto-Updates
Downgrading is a technical process. While generally safe, improper handling can cause device issues. Phase 1: Preparation