Spektrum S6040 servo jittering

Just installed 2 brand new S6040 digital servos on my KH build for shifting and steering. Plugged everything in and they started tweaking out (see video below) they were powered using a mfc-01 with an AR9020 receiver dx9 tx. I tried using different servos using the same set up which worked fine. I plugged the servos directly to the receiver using a 6v battery and they worked fine. I've tried different batteries, receivers, mfc-01, radios etc. I checked the Spektrum website and saw they require 4.8-6v of power, voltmeter showed 4.75v at steering and shift servo output on mfc-01. I like these servos because of their speed, hate to get rid of them. Any ideas?

https://youtu.be/gMvLvZqRkfo

Note that all movements you see are on its own. I never touched the transmitter