OxygenOS 11 will immediately detect newer software versions and attempt to download Android 12 or 13 again automatically. To preserve your Android 11 setup, navigate to > System > System Updates , tap the gear icon, and switch off Auto-download over Wi-Fi . If you ran into any snags during the process, let me know: Your exact OnePlus 9 model number (e.g., LE2111, LE2115) Your current Android version (Android 12 or 13) The error message you saw on the screen
If you are facing specific errors during the process, please share: Your exact (e.g., LE2115, LE2125). Your current region/carrier (T-Mobile, India, EU). The exact error message you are seeing. What Android version you are currently running. Downgrade Oneplus 9 To Android 11
To prevent your phone from instantly upgrading back to Android 12 or 13, go to > System > System Updates . Tap the Gear Icon and toggle off Auto-download over Wi-Fi . Troubleshooting Common Issues OxygenOS 11 will immediately detect newer software versions
Download the firmware file. It will be a large package (usually between 3GB and 4.5GB) ending with a .zip extension. Your current region/carrier (T-Mobile, India, EU)