My nephew has an Ender 3 Pro 3D printer he is borrowing and he started having trouble with the filament feeding. I don't have any experience with 3D printers so I'm limited on what I can help with. He said it will print for maybe an hour and then it will stop and it looks like there is some kind of problem with the part that grips the filament and feeds it. He read up on it online and he replaced some M3 screw to a longer screw, which people advised and it helped, but the problem is still there. Anyone have experience with this printer that can help?