I am curious to know why that happens as well. I just went through having to change the filament 3 times to get it to run and load correctly. With 35 minutes left on a 10 hour print, the printer thought there was a filament feed issue. So I did a ‘change’ process and heard the clunk at the end of the loading. From experience I know it means the feeder has chewed up the filament at the very end of the load. I finally got a good load, by unlatching the feeder handle, manually removing the filament, clipping off all the material that was forward of the brutal chew marks, and re-inserting the filament all the way to the print core. Would be great to know why it happens so I can fix it quicker and not waste 1m+ of filament.