Took me more than 3 months to figure that out. Turn up your extruder stepper driver.
feel the filament right as it goes into the extruder. You can feel it pulse, turn up the driver until that pulse goes away. Let it print a while and make sure the stepper doesn’t get too hot. Something fishy about the MK8 knock offs, they all take vastly different power. I have 1 at .55v and 1 at 1V Identical steppers.