OnePlus is currently rolling out its first update to the OnePlus 6 and 6T since July, and users are rightly a little annoyed that it's taken so long. That means three months without the latest security patches, and if you're expecting a sizeable update with exciting new features, sadly this isn't it.
As the below changelog points out, only stability improvements and bug fixes accompany the OxygenOS 10.3.6 update for these two phones. The company is likely focussing its energy on its OxygenOS 11/Android 11 builds now, so it's not unexpected that this would be a light update. More regular security updates would please users no end, though.
- Improved system stability and fixed general bugs
- Updated Android Security Patch to 2020.09
As part of what is the usual staged rollout, the update will hit a limited number of 6 and 6T phones to begin with. Once certain that no critical issues are on board, OnePlus will commence wider distribution. So be patient and it'll get to you eventually. It's unclear how long it will be before Android 11 comes to these two-year-old phones, but OnePlus did promise they would get it at some point, which is something.