OxygenOS 12 and newer removed the built-in local upgrade option. Here is how to restore it:
Ensure you download the rollback package that matches your specific regional hardware model (e.g., North America, Europe, or India). Installing the wrong regional firmware can cause network connectivity issues. Step 1: Back Up Your Data
Before diving into the “how,” it’s worth understanding why many OnePlus 9 owners choose to revert to Android 11. When OnePlus began rolling out the Android 12 update (OxygenOS 12), a significant number of users reported performance issues, battery drain, and connectivity problems. In some cases, early beta releases even bricked devices outright, forcing OnePlus to pull the download links. For those who value stability and smooth performance, Android 11 remains a well‑optimised and reliable foundation for the OnePlus 9. downgrade oneplus 9 to android 11 exclusive
Shortly after the OxygenOS 12 update, the OnePlus community forums, Reddit, and Twitter exploded with complaints. Users reported the update was “extremely buggy” and lacked many customization options present in OxygenOS 11. Gadgets360 noted that the update “reportedly removed customisation options” and that early adopters “say that they can't customise icons, status bar, battery icons, or turn the Google Feed off”.
: Your phone must have at least 60% battery life to ensure it does not power off mid-installation. OxygenOS 12 and newer removed the built-in local
| Issue | Probability | Workaround | |-------|-------------|-------------| | Widevine L1 → L3 | 100% | Permanent due to TAMPER flag | | Fingerprint sensor lag | 20% | Re-enroll after 3 reboots | | 5G NSA not connecting | 15% | Flash modem from CPH2179_11_C.15 | | OTA notification spam | 100% | Use NetGuard firewall to block *.oneplus.com | | Google Pay/SafetyNet fails | 100% | Install Magisk + Universal SafetyNet Fix v2.4.0 |
The OnePlus 9 arrived with Android 11, promising a fast and clean experience. However, subsequent updates to OxygenOS 12 and beyond brought a unified codebase with OPPO’s ColorOS, which many users felt stripped away the "OxygenOS feel" and introduced bugs. If you are experiencing battery drain, UI lag, or simply miss the clean, customizable interface of , this guide will help you downgrade your OnePlus 9 to Android 11 exclusively . ⚠️ Critical Disclaimer: Read Before Proceeding Step 1: Back Up Your Data Before diving
If Android 11 becomes unstable, revert using (not fastboot). Download the correct ops file for your model. MSM bypasses all partition locks by rewriting at the Qualcomm Sahara protocol level.
After downgrading to Android 11: