That’s a very interesting issue! In my line of work, I constantly troubleshoot issues on electronic devices and software, so I find it fascinating.
The problem that you see with the stuck pixels etc is in all likelihood a partially corrupt or incomplete video feed. If you download a video online and try to play it before it has finished downloading, you’ll see exactly the same artifacts coming up.
The fact that the problem is not showing when you try other resolutions -even higher- and only when you choose 2.7K at 60 FPS, leads me to suspect the high FPS rate. Could you please try the following?
1. Record new video at 1080p/60 FPS and even higher frame rates?
2. See if you can record a video at another high rate like 50 FPS (I know that GoPro cameras allow this by switching between PAL/NTSC)
Is the corruption happening with these settings also?
By the way, if the problem only occurs when you are recording video and on multiple devices then this leads me to the following train of thought:
1. The issue is happening on multiple devices, 2 of which are/were flagship phones. So the device itself can be excluded.
2. The issue is not in the feed in and of itself (and that includes signal interference) as when you stop recording the glitch goes away and the video is fine, regardless of the distance.
3. In both cases (recording or not) the feed received is 720p (30 FPS I think?), which begs the question: does something change to the actual feed when you press record?
4. If not, then we need to look at the drone itself. It is recording video at a high frame rate and streaming it at the same time to the phone. Is it struggling to provide the feed?
5. Also, another suspect is the DJI app and/or drone firmware. Was the issue there from the beginning or did it happen recently? If the latter, did it occur after some update to the software on the phone and the drone?