I got an ender 3 for Christmas today and have set it up. So far, everything else works (motors, heat, etc) but the extruder doesn't seem to work. I have tried to level my bed but when I level it so a piece of paper can easily slide under the nozzle while touching both the bed and the nozzle, no plastic extrudes. If I level the bed too far down, plastic comes out the nozzle (Can't tell if it is just drips or the extruder is working). Any thoughts on a fix?