On a 1010 head, in real "bushy" wheat, it would do something similar. There would be a swirl effect for the wheat about 3 feet wide, right in front of the feeder house. Those fingers just weren't long enough to pull it in.
With a 1010, if you drive above the speed where that starts to happen, you'll end up not cutting all the straw in that patch right in front of the feeder house. Unfortunately, we never found a good solution to this other than just driving slower. It wasn't common, but when you're cutting wheat like this, a 36' draper will still make a clean cut at speeds faster than what that 30' 1010 would. The drapers don't have this bunching issue, as there is no auger to hold the pile back.
The sickle on a 1020 is a few inches farther forward than a 1010, so I'm not sure if you'll ever see the pile build up far enough to not cut the wheat right there.
-Lance