Are you one of the bodacious and curious folks who decided to install the Android 11 beta when it dropped? Did you decide to do so on a Google Pixel 4 or 4 XL? If the answer to both of those questions is “yes,” you can forget about downgrading back to Android 10.
Users across the web [particularly on Reddit (1, 2, 3, 4)] are reporting that trying to revert back to Android 10 on their Pixel 4 or 4 XL results in failure. I’ve had the same problem myself. Android 11 has been causing some battery drain issues and other despicable bugs on my 4 XL (classic beta, amirite?) so I decided to reinstall Android 10. When I opt out of the Android beta program through Google’s own website, I get a notification on my Pixel telling me the update to erase my phone and reinstall Android 10 is available to download. I proceed to download it, install it, and reboot my device.
It’s during the reboot that myself along with many others are experiencing a problem. It seems that all of our devices get stuck in fastboot mode midway through the reboot. I manually try to reboot my Pixel only to watch my device come back to life, present the get started screen, and still be running Android 11. I’ve done this process twice and all it does is erase my phone. I can’t get Android 10 back.
Granted, some users on Reddit have reported unlocking their bootloaders and flashing a fresh copy of Android 10 on their Pixel 4s seems to work. But you shouldn’t have to do that, especially since Google gives you a consumer-friendly way to get Android 10 back in the first place. No one knows why this issue exists. It might have to do with locked bootloaders, but I tend to doubt that since Google had to anticipate people would install the beta on phones that were still under contract through carriers.
Multiple support tickets have been opened with Google so there’s a chance that a Google-provided solution is imminent. But be forewarned: if you want to test Android 11 on a Pixel 4, you more than likely will be stuck there until either Google has a fix or Android 11 is officially released to the public, whichever comes first.