OnePlus has announced and started rolling out OxygenOS 10.3.1 for the OnePlus 6 and 6T. The latest stable update for the devices addresses a host of issues while also improving system and camera performance.
https://www.notebookcheck.net/OnePlus-rolls-out-stable-OxygenOS-10-3-1-bug-crushing-update-for-the-OnePlus-6-and-6T.451172.0.html