Downgrade Oneplus 9 To Android: 11 Exclusive
Android 12 updates the modem firmware (DSP, ADSP, modem). Android 11’s modem expects older signatures. A mismatch leads to:
To downgrade your Go to product viewer dialog for this item. downgrade oneplus 9 to android 11 exclusive
A warning will appear stating that this will reset your device. Tap Confirm to start the installation. Android 12 updates the modem firmware (DSP, ADSP, modem)
to Android 11 (OxygenOS 11), you must use a specific provided by OnePlus . This process will erase all data on your phone, so backing up your files is essential. Preparation downgrade oneplus 9 to android 11 exclusive
Bricked phones or complete clean flash to Android 11.