Even for OnePlus it begins to become difficult to manage all its devices, therefore as happened for other rival brands the word End to the Oper Beta program relating to OxygenOS for OnePlus 6 and 6T is put. The announcement is made by the company through the official forum thus explaining also roll back to the stable version of the UI.
The reason for this choice undoubtedly lies in wanting to ensure the smooth functioning of the Beta program and introduce new devices. So the owners of OnePlus 6 and 6T will be able and will have to return to the stable version OxygenOS 10.3.2 via rollback, considering that the updates will continue to arrive but only in stable format. Finally, it should be noted that the transition from beta to stable via rollback will erase all data on the device, so it is advisable to backup your most important data.
OxygenOS Open Beta ends for OnePlus 6 and 6T: here's how to roll back
IMPORTANT: The procedure described in this guide presents complex operations which, if performed incorrectly, could damage your device. It is recommended to run it only by users who have gained a good experience in modding. For more details on the procedure, please refer to thread on the official OnePlus forum.
Having made the necessary recommendations, therefore, to proceed with the rollback procedure you must download the package dedicated to your device OnePlus 6 or OnePlus 6T. From your smartphone's File Manager, move the package you just downloaded from the Downloads folder to the root directory.
Now get in Settings, System, System Updates, press the button at the top right and choose the Update via local file option. Now select the downloaded package and start the procedure.
