Under extrusion? been printing with the Creality K1 AI max for a few months now, and everything has been going great. Until last week, prints have been failing everything. it appears to be under extrusion, the filament just stops coming out. I am not sure why, nothing has changed. Sometimes it will fail early and others later in the print, but always appears to be under extrusion. I have used this filament many times and have had flawless prints in the past. I have tried changing to a new roll of filament, tried a different brand and color of filament all with the same result. I cleaned the machine, swapped the nozzle, and replaced all the bowden tubes, but still the same result. Does anyone have any ideas what the problem could be? or suggestions to try?