I've looked at both factory files ...and there's only one real difference between them, and that is one has a global-z offset of -0.08mm and the other (the one that allegedly prints wrong) has a global-z offset of -0.12mm.
I'm wondering if the firmware on the Tevo Tarantula has some form of z axis limiting or protection built into it.....where its not allowing normal printing below say -0.1mm by backing off the extruder feed.
This, to me, is a logical explanation as to why you're getting the reported symptoms of the extruder motor not being powered. If the motor was being powered, I would have suggested the print nozzle is too near the bed....thus preventing filament from being pushed out the nozzle.
Of course, the extruder motor could be under powered....and the nozzle being too close to the bed, resulting in the filament being mechanically held back, and there being no signs of physical stress on the motor....ie not getting warm & no mechanical or electrical "slipping".....which would explain how you could "hand feed" just the right amount of filament to give a good fill!!
A possible solution.....stop using the global-z setting to fine tune the bed position and use the bed screws.