krazyfrog, May 25, 2019 : My OnePlus 7 Pro unit is having issues playing back 60fps videos in the YouTube app. Videos in 60fps frame rate keep fluctuating between 60 and 30fps frame rate while the video is playing. This applies to all three resolutions where 60fps is supported in the YouTube app on the phone: 720p, 1080p and 1440p. It applies to both, SDR as well as HDR videos. The issue is very easy to notice if you can tell the difference between 60fps and 30fps. The video will go back and forth between the two frame rates and it's extremely jarring. Here is a sample video to demonstrate the difference. Now, the issue could very well plague all videos in the YouTube app but since it pertains to the frame rate, it can only be noticed on high frame rate videos. I have tried playing 60fps video files locally on the device and they all play at the correct frame rate without any switching. The issue seems to be limited to the YouTube app. The app itself has received an update or two since I noticed this issue and has also been working fine on other smartphones so the issue is not related to the app itself from what I can tell. I also checked the video stats while playing and there were no reported dropped frames by the YouTube app and it seems the app seems entirely unaware of the frame rate going back and forth on the display. This means the issue seems limited to OxygenOS and how it's handling the video from the YouTube app. As someone who does watch a lot of 60fps content on the phone, this issue has made the YouTube app unusable for me so I'm hoping someone from the OxygenOS team sees this and releases a fix for it.