9RT received C.05 on 4th August, but we hadn't updated the article with its changelog at the time:
Changelog for OOS12.1 C.05 (second stable)
- Improves system stability
- Optimizes the experience of fingerprint unlocking
OnePlus Community post is finally up, added its link.
The 9RT (released only in India) received an OxygenOS 12 Open Beta (C.03) on 24th June 2022, and got the first OOS12.1 stable build (C.04) on 27th July 2022.
There isn't any forum post up yet. It went live on 5th August 2022.
With every new device receiving OOS12.1, we always advise our users to be patient and not jump into it without thinking. Every "first build" — even stable — is usually quite buggy and is almost always met with general disappointment. For example, 9-series got the first stable build on 6th December 2021, which was pulled shortly after rollout. Every device has received a few bugfix releases, but users are still complaining about genuine bugs. For example, my 8T is on the latest release for it (C.21), but none of these issues are still fixed (other devices also have some of these bugs):
- Android Auto shows a "searching for GPS" warning; makes it very difficult to navigate unfamiliar roads (e.g. on a trip)
- Double tapping on the lockscreen doesn't always turn screen off
- USB choice dialog pops up every single time, even though I've already set a default
- Going to the home/recents screen from an app that supports Material You's dynamic colour lags like crazy, regardless of using gestures or buttons
Anyway, if you wish to update to C.05, you can do so via the app itself, since full ZIPs are available. Rollback instructions are at the end of this article.
Back when the 9-series got their first OOS12 build, OnePlus had posted a short FAQ to prepare users. You can go through it if you haven't already: https://community.oneplus.com/thread?id=1519491. There's a "peek inside OOS12" thread as well: https://community.oneplus.com/thread?id=1529132.
Changelog for OOS12.1 C.04 (first stable)
- New design
- Optimized desktop icons with improved textures, by using a design inspired by brand-new materials and uniting lights and layers
- Newly added Quick launch, a feature that detects the apps you use frequently and pre-loads them so you can open them quickly
- Newly added a chart to display your battery usage
- Optimized the auto brightness algorithm to adapt screen brightness to more scenes for a comfortable screen reading experience
- Dark mode
- Newly supported three adjustable levels, bringing a more personalized and comfortable user experience
- Newly added style options for Cards, making data contents more visual and easier to read
- Newly added Earphone Control Card with Bluetooth earphone one-click adjustment
- Newly added access to OnePlus Scout in Shelf, allowing you to search multiple contents on your phone, including Apps, Settings, Media Data, etc
- Newly added OnePlus Watch Card in Shelf, to easily glance at your health status
- Work Life Balance
- Newly added Work Life Balance feature, allowing you to effortlessly switch between Work and Life mode via quick settings
- Supported automatic Work/Life mode switching, based on specific locations, Wi-Fi network, and time, also bringing customized App notification profiles according to the personalization
- Newly supported switching between different layouts with a two-finger pinch gesture, intelligently recognizing the best-quality pictures, and cropping the thumbnail based on the content, making the gallery layout more pleasing
- Canvas AOD
- Newly added diverse styles of lines and colors, for a more personalized lock screen experience with inspiring visuals
- Newly added multiple brushes and strokes and support for color adjustment
- Optimized the gaming experience in team fight scenes
- Newly added the HyperBoost end-to-end frame rate stabilizer
- Optimized the display of camera modes on the menu bar
- Optimized the experience of zooming in or out when shooting videos with rear camera
- Newly added visuals to text instructions for an intuitive understanding of accessibility functions
- Newly supported more system apps in TalkBack, including Photos, Phone, Mail, and Calendar
- Optimized categorization of functions by grouping them into vision, hearing, interactive actions, and general
You'll notice that this changelog is the exact same as Open Beta 1's. OnePlus tends to use the exact same changelog for the first OOS12 release, regardless of device or it being stable/beta.
Where can I install stable OxygenOS 12.1?
If you're currently on the stable track, you should have already received a notification from the app about the C.05 update. Please ensure you've selected either of the stable update methods in the app's settings, since the beta track doesn't receive updates separately from stable anymore (post Oppo-merger). Beta track is now meant only for the first few major Android builds, nothing more. Disable advanced mode as well, in case it's turned on for whatever reason. The stable track will continue to receive updates until the device is marked EOL (End-of-Life).
Once you're on the main screen of the app, simply download the update presented to you and follow the installation guide. Note that 9RT was released only in India, so there are no other regional builds for this device.
Can I revert to OxygenOS 11?
Yes, go through the community post for detailed instructions. Rolling back will completely wipe all your data, so please take a backup before proceeding.
Below is the rollback/downgrade packages for the OnePlus 9RT. Make sure you choose the correct rollback package for your device and region. We are providing these links purely for your convenience, as rolling back isn't natively supported by our app. After downloading the correct rollback package, move the file from the "Downloads" directory to the topmost directory of internal storage (the same directory that the "Downloads" folder is in).
Then, open Settings -> About device -> Version and tap "Build number" 7 times. This will enable Android's built-in "developer mode" (you might have to enter your phone's PIN/password too). Once this is done, "Local upgrade" will once again be visible in Settings -> About device -> Up to date -> top-right button.
The following packages will rollback your device to OxygenOS 11.3 (A.07), and will wipe all your data.
Remember: these are rollback packages — they're not the packages you should download if you're looking to update to the latest stable version. For that, close this news article and ensure you've selected either of the "Stable" update methods in the app's settings.