Took some video today and experienced this. Was new to me and different than jello that I had seen before.
Today's effect was generally experienced when aiming toward the sun.
I was using auto and 30 fps.
After reviewing the other footage it does show up multiple times, but always at roughly the same camera angles relative to sun and horizon.
I was not using an ND filter.
I'll go back tomorrow, wind permitting, and have some more time for experimentation.