OnePlus 6 OxygenOS 5.1.7 update has been released with fix for bootloader bug (an issue that had been widely reported since the launch), fix for DND (Do Not Disturb) schedule setting issue, general bug fixes and various other improvements. The OTA update weighs around 64MB and starts getting on several regions, however it will not be available in India due to some issues.
Recently, OnePlus rolled out OxygenOS 5.1.6 update for the device, but it was paused for Indian users due to stability issues. OnePlus 6 users in India will get OxygenOS 5.1.8 update next week with a fix for the known issue, along with all the features that come with OxygenOS 5.1.7.
A major change in this update is bootloader vulnerability fix. The updated bootloader will prevent the physical access to OnePlus 6 to boot any arbitrary modified image without unlocking the bootloader.
– Fixed schedule setting issue for Do Not Disturb (DND) mode
– Updated bootloader for system security enhancement
– General bug fixes and improvements
If you own a OnePlus 6 and have not received the OTA notification for this update yet, check it by going to About phone > System Update. If update found, download and install it.
If you prefer manual installation, you can install the update manually by downloading the full firmware. You can download the full firmware from OnePlus download page and flash manually as described below.
Manual Installation Instruction
1. Download OxygenOS update zip file for your device from here and place it on your device’s internal storage.
2. On your phone, go to Settings > System update > Settings (tap on cog icon on the top right corner) > Local upgrade.
3. Locate the OxygenOS update zip file and tap “Install” to start the installation.
4. The update process will take few minutes. Once done reboot your device to boot into the latest Oxygen OS. (Source)