My relatively new Ender 3 S1 Pro with default extruder started to under extrude and jam on some layers. When it happens I can hear extruder skipping/clicking noises. I printed same g-code multiple times and happened on different layers.
I replaced the nozzle (default 0.4) with the new one (same size/type, from Ender's 24Pcs Brass Mk8 pack), but got similar results.
I removed and checked the nozzle and throat, but didn't see anything abnormal, there was no filament between the nozzle and the throat.
I tried using different SD cards, tried different extruder temperatures.
I'm running default latest firmware from Ender. I haven't performed any PID tunes or any other firmware changes, I've just changed the nozzles and adjusted screw/belt/roller tensions.
The models were sliced on Cura v5.3.0 on Mac and Windows versions (default Ender S1 Pro profile).
I don't think it's a filament or slicer issue as my Tronxy CRUX1 printed same model with the same filament just fine.
What could be the main causes for such jams/under extrusion?
Under extrusion example:
Nozzle and throat:
