Maybe the phone or device you are playing it back on, can't handle the video quality, mines the same until I view on my 4K tv, then all is perfect,
But I don't think that's the issue here,
It's signal related for sure,
Looking at your video it plays fine on my iPad except the juddering,
But I see what you are saying, I'm no expert but to me that seems like interference with the wifi to the device you had connected,
I'm no expert by any means, I've only owned my P3S for just over a week,
How strong was your wifi signal when looking in the Dji go app ?,
Maybe try in an open field and see if it persists,
Get into some open space and see if it goes away,
If the aircraft was flying fine, then it has to be something interfering with the wifi for the video downlink,
If so then it's interference from your surroundings
Just a thought, I could be completely wrong,
But I stand corrected.
Sent from my iPad Pro using PhantomPilots mobile app