The China variant of the OnePlus 9 series comes with Color OS instead of Hydrogen OS by default, which is not good news for geeks as Color OS has many limitations compared to Hydrogen OS. Recently, OnePlus has officially provided a way to switch between Color OS and Oxygen OS.
Please note that switching systems will clear all user data, so you better know what you're doing.
· Switch from Color OS to Oxygen OS
Download the downgrade package for the appropriate model and system and put it in the internal storage.
Installation steps: Settings - Software update - Settings (top right corner) - Select installation package - Select the previously downloaded downgrade package - Install now - Install now
If the Select installation package option is grayed out, it means that you now have a pending system update and you can choose to install or skip it.
To skip update: Settings - App management - App list - Menu (top right corner) - Show system - Software update - Storage usage - Clear data - OK - Disconnect all network connections
· Switching from Oxygen OS to Color OS
Download the downgrade package for the appropriate model and system and put it in the root directory of the internal storage.
Installation steps: Settings - System - System updates - Settings (top right corner) - Local upgrade - Select the previously downloaded downgrade package - CONFIRM
Just reboot your device after the installation is complete and have fun!
It's not a deal breaker for me since we can manually get 5G from the dialer. However, the functionality is there but it somehow needs an update from Oneplus to add 5G from the preferred network. I really hope Oneplus would fix these issues.