Until recently, joining the Android Beta program was pretty straightforward, as users could join via the Android Beta website and receive each new build until a stable version was released.
Except that with Android 12L beta, not everything went perfectly and users, when the stable version was released, began to automatically receive the new Quarterly Platform Release (or QPR) beta versions, with the consequence of being subject to the risk of finding themselves with a device affected by even significant bugs.
Fortunately for those who have found themselves in this situation, there is a not too complicated remedy to get out of it. Usually, disabling the beta program via the official website initiates a process in which the device downloads and installs the latest stable version of Android and then performs a factory reset, erasing user data – for that very reason, many prefer to stay in the beta program until it ends.
How to avoid deletion of all data with Android 12.1
However, there is an alternative, as if the device is already running the same stable build that would be installed by deactivating the beta program, you can completely avoid the process (and the deletion of data).
Some users have found a way to exit the beta program without erasing data and for it to work it is necessary not to have installed the QPR3 Beta 1 update. That said, you need to download and install the 12.1 stable OTA package for your device (the page with the various packages can be found by following this link).
Once the stable OTA version is installed, you need to go to the Android Beta program website and remove the device and if everything is done correctly, the data should not be erased nor should any updates be installed (this is because the stable package has a newer release date than the beta version which is superseded).