The problem can apparently be fixed via a software update and has affected the OnePlus 3/3T as well
Information circulating the Internet suggests that the OnePlus 5 suffers from yet another odd problem. When recording video, stereo audio channels don’t adjust to the phone’s orientation. If the smartphone's home button cum fingerprint sensor is to the left, then you get the correct stereo sound. But if the home button is facing the right then you will get inverted audio.
Every phone that can record stereo audio in videos uses a microphone on either side of the device to gather sound and classify it as left or right audio channels. As mentioned above, the phone can be held in two different landscape orientations. In either case, smartphones can record stereo sound based on the orientation. The audio channel is switched and assigned according to the orientation the user holds the in. The OnePlus 3/3T and 5 don’t do this. Information circulating the Internet suggests that this problem is something OnePlus can fix with a software update. This problem has existed on the OnePlus 3 and 3T, but it has risen to light just now.
OnePlus 5 smartphones were recently reported to face a Jelly Scrolling effect and the company claimed that the effect is “natural”. The XDA developer’s forum has confirmed that OnePlus mounted the display panel upside-down on the OnePlus 5, which is probably causing the Jelly Scrolling effect.