A number of OnePlus 6 users have taken to Reddit, the OnePlus 6 support forum and other sites to complain about an issue with the phone's display. Apparently, with adaptive brightness enabled, the screen flickers under very bright sunlight. Very slight movements by the person holding the device seem to kick off the flickering as it appears to be shifting back and forth between two different brightness levels. Those who have experienced the bug say that it is more noticeable with content that is mostly white, and those featuring vivid colors.
5.1.8. The more recent update to version 5.1.9 did not fix the problem. One OnePlus 6 user cleared the cache on his unit and said that it fixed the problem, at least for the time being.The issue first appeared last month after OnePlus pushed out the update to OxygenOS
OnePlus has reached out to at least one of the Reddit posters and requested a log with a recording of the screen. The fact that the manufacturer knows about the problem is the first step to having a patch released to fix it. In the meantime, we should remind you that not every OnePlus 6 is experiencing this problem, and you can always disable the adaptive brightness feature until the issue is resolved.