This is OxygenOS 10.5.4, still based on Android 10 of course. The aim here seems to be to fix a lot of issues and enhance the general system features. The full changelog is the same for both phones, and it is quite large.
Here’s what it entails:
•Improved system stability
•Improved icon display in status bar
•Imporved back gesture experience
•OnePlus Bullets Wireless Z can now be integrated with Dolby Atmos for better sound quality
•Added double-tap feature to wake up lockscreen in ambient display mode or off-screen condition
•Added OnePlus Tips & Support section in Settings. Check out all the new features and answers to common issues here
•Added Live Caption, this will detect speech in media and automatically generate captions [To enable: Settings-System-Accessibility-Live Caption]
•Update Android Security Patch to 2020.03
•Updated GMS package to 2020.02
•Optimized the camera’s shooting experience and improved stability
•Optimized the animation effect and improved interaction experience
•Added video filter feature
•Optimized the fingerprint unlock experience when unlocking the device
•Added contact notes info for incoming calls
•Optimized network data transmission performance and stability
Voice Assistant updates
•Now you can wake up voice assistant of your choice just by long-pressing the power button [To enable: Settings-Buttons & gestures-Press and hold the power button-Choose the app you want to activate]
As you can see, even after applying this update you’ll still be on the March 2020 security patch level, which is a month old at this point. Hopefully OnePlus will get better about timely security updates in the future.
With the new software, the OnePlus Bullets Wireless Z, which were announced alongside the new smartphones, can be integrated with Dolby Atmos to provide you with better sound quality.