one nozzle clog after another. I have bought a K1 and for 2 weeks it printed great. but now I have cloggs with almost every print. I did cold pulls. I replaced the PTFE tube (Capricorn) between extruder and hotend in the toolhead. but nothing helps. what I see is that the filament seems to get soft in the small PTFE tube between hotend and extruder. So it's a heat creep... the hotend fan is running. I haven't changed any setting. all is running with stock setting through Creality print. what should I do?