Downgrade Oneplus 9 To Android 11 -

Ensure your phone is charged to at least 30% (60% is recommended) to prevent power loss during the flash.

Downgrading your OnePlus 9 to Android 11 is a relatively straightforward process, but it does require some technical expertise and caution. If you're not comfortable with the process or encounter any issues, it's recommended to seek help from OnePlus support or a professional. However, if you're willing to take the necessary precautions, downgrading to Android 11 can provide a more stable and familiar experience.

| Issue | Workaround | |-------|-------------| | "Verification failed" in Local Upgrade | Rename file to downgrade.zip , try again, or use MSM | | Fingerprint doesn't work after downgrade | Reboot twice, or re-flash persist.img from OOS 11 backup | | WiFi / Bluetooth broken | Flash OOS 11 persist + modem via fastboot | | Anti-rollback error (bootloop) | Your OOS 12/13 had higher ARB version – must use MSM Tool |

Move photos, contacts, and documents to a cloud service or a PC. Battery Charge: Ensure your phone is charged to at least 30-50%. Verify Model/Region:

: Choose the rollback ZIP file you downloaded. A warning will appear stating that your data will be erased.

: Visit the OnePlus Community forums or official support pages to download the correct OxygenOS 11 rollback zip for your region (India, North America, or Europe).

You will see a progress bar. The screen may flicker – this is normal.