Last tested: OnePlus 9 LE2115_11_C.15 (Android 11) downgraded from LE2115_13_F.75 (Android 13).
to Android 11 (OxygenOS 11), you must use a and a specific local update APK , as the standard system settings often hide the local upgrade option on newer Android versions. Critical Pre-Checks downgrade oneplus 9 to android 11 exclusive
OxygenOS 11 maintains the "classic" OnePlus look, whereas Android 12 adopts Oppo’s ColorOS design. Stability: Users report significantly fewer bugs and smoother performance on Android 11. Customization: Last tested: OnePlus 9 LE2115_11_C
: This process will erase everything on your device, including photos, apps, and settings. downgrade oneplus 9 to android 11 exclusive
If the rollback file ends in .jar , rename it to remove the .jar extension so it ends in .zip .