Hello I print a grave candle for my grandparents. The walls of this candle are made of lithophane. When printing the last wall, the filament got stuck in the head twice in the same place and although the head worked, nothing printed. I made two attempts to print and in both of them the filament jammed at the same time (I had to disassemble the motor to remove the blockage). Do you have any idea why this is happening?