Current measurement

Hello,

i tried the search function but did not find the answer. Maybe someone can give advice on my problem. 
i am using a HGLTECH vesc 200 A Max 75v 

i am running a sss56114 innerrunner 6 Pole Motor on 12s liion. 
i know from previous measurement that this motor uses around 4A no load current. Wit the attached planetary gearbox slightly more. 
with the vesc and attached metr can, I get readings of about 2A only. 
 

How can that be?

thanks

Toto