Shedding teeth in my opinion. I have kept ATF for 25 years and I know exactly what you are talking about. Snappy real fast while it moves forward a few inches then shakes its head a few times.
Mist of my ATF have simply been twitchy fish. I'm partly convinced thatbitbis just their character. They're like a 1000 horsepower old school muscle car; they can hold still at times, but they are barely contained balls of raw power and speed.
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