Printing issue on Ender 3V2
Print the same file, with the same settings, on both machines.

If the problem persists, try swapping the filament between the two printers. If the problem now occurs on the other printer, that suggests that the filament is the issue. Label the bad one &quot;For lumpy prints&quot; and put it away.

If the problem persists on the printer where it first occurred, despite swapping filament reels, the issue probably has something to do with the printer. Remove and examine the nozzle, and consider replacing it even if it looks OK. Nozzles are cheap and easy to replace, so this is an easy early step.

If a new nozzle doesn't fix it, other parts related to the extruder like the hot end thermistor, fans, heater block, etc. could be to blame. If the thermistor is just positioned a little differently than on the &quot;good&quot; printer, for example, it might be reading a little low and causing the nozzle to heat up more to get to the target reading. That doesn't necessarily mean that you have to replace those parts; you just need to recognize the difference and compensate for it when you use that printer. Just as a baker might think &quot;the recipe says 400 °F, but I know my oven runs hot, so I'll use 375 °F instead,&quot; you may need to adjust the nozzle temperature to compensate for the hardware differences when you use this printer.