Hello everyone,   I am having trouble with some strange underextrusion. In some prints, maybe 1 out of 10 and in only certain parts, the PLA is extruded in little pulses that increase in frequency untill they turn into a smooth line. This always happens at the beginning of a new layer, after z-hop and retraction. Due to this the print is massively weakened at these parts and shows striations on the surface. I managed to capture this on video and also have a picture of it, but I have no