It's Skip shift.
You can either:
1. Unplug the solenoid (need some way to plug and secure the loose cable)
2. Tune the powertrain.
I've personally just learned to counter it by first swinging it through neutral quick before dropping it into 2nd. That sweeps seems to clear the lock and engages 2nd all the time.
It's annoying but it's also what allows Ford to claim 26 MPG HWY and avoid the gas guzzler.