Extruder chewing through filament  

Extruder chewing through filament

I just finished building a MINI+ kit. This will be my third MINI, and my 6th Prusa in total. It is the 3rd kit build, but my first kit MINI (since they didn't come as a kit when I bought the first two). I took my time and followed the instructions very carefully.

I'm printing with Prusament PETG, and am having trouble with the extruder grinding through the filament about 15 minutes into the print. I then have to pull it out manually, at which point I find a chewed-through portion of the filament.

This is different then the "clicking" issue that I ran into on my previous MINIs, where heat creep seemed to cause a clog in the cold side of the hotend (that issue was resolved with a Bondtech heat break, but I suspect that Prusa Research has fixed this on current-shipping printers). It does not click, it just manages to chew through the filament and stop extruding.

I have checked the hotend temperature, PrusaSlicer profiles, the entire filament path up to the top of the hotend, the idler tensioner, the filament sensor, and everything else I can think of, but I am not finding the culprit for what might be causing this. I have also disassembled and reassembled the extruder three times and have found no issues (other than chewed up filament).

If anyone has ideas, I would love to hear them!