At its I/O developer conference last month, Google announced that, for the first time, non-Google devices would be getting access to the Android developer preview builds, with devices from manufacturers such as Nokia and OnePlus showing up on the list. One of those devices was the Nokia 7 Plus, which received its first preview shortly afterward.
The device missed the recently released build of the upcoming operating system, and it now seems as though Nokia is removing users from the preview entirely. While it's unclear whether this is intentional or not on HMD Global's part, many users on the Android P beta program received an update claiming to include Google's security patch for June only to find out that they had been downgraded to Android Oreo after the update installed.
The fact that the update package was a whole 1.3GB in size might have been a sign that it wasn't a mere security update, but there was no indication of what it contained aside from that.
After the downgrade, users are running into a high amount of crashes and irresponsive applications, as the data on their device was meant to be on the newer version of Android. It's also impossible to roll back using the package provided on Nokia's Android P web page, as it's older than the version users now have.
Beta programs and developer previews are commonly expected to contain major bugs and issues, but being inadvertently downgraded to a previous version of Android is certainly a complicated predicament. Users can, at least, do a factory reset on the phone to return to a more stable experience on Android 8.1 Oreo. Nokia hasn't provided much comment on the situation, with a moderator on Nokia's community forums saying that the issue will be investigated.