When recording video in landscape mode with the headphone jack pointing left, the device switches the left and right audio channels. This means that stereo audio is pretty much broken. Watch the video in headphones or close to some stereo speakers to see the issue. Recording with the headphone jack pointing right works just fine.
Thankfully, this is something that should be easily corrected via software update rather than a warranty exchange. Still, it’s a funny oversight on the part of OnePlus, and one that’s present on the OnePlus 3T as well. How many of you have this issue? Leave a comment!