MATERIAL (PLA) STOPS FLOWING OUT AND IT GETS A CERTAIN FORM THAT DOESN' LET THE MATERIAL RETRACT TO BE CHANGED I HAVE TO GET THE BOWDEN TUBE OUT AND PULL IT FROM THE HOT SIDE END . ALREADY CLEANED THE HOT PART AND SAME PROBLEM OCCURS AFTER THAT. I DON' T KNOW WHAT OR WHERE THE PROBLEM IS OR WHAT TO CHANGE . PICTURE OF THE MATERIAL ENCLOSED.