My Ender Pro 3 is still basically new. It has only completed about 6 print jobs in the 6+ months I have had it. The extruder will pull the filament into the tube. It will continue to feed it till it gets to the hot end. Once it gets there, it will spins but no more filament will enter and the filament begins to grind. If I push the filament in, it comes out of the hot end. That tells me it is not a clog. It is as if the extruder does not have enough force to push once it gets there. I have tightened up the extruder handle until it began clicking and then backed it off just a little. Thoughts?