Hey I just saw your update! I’m glad you’re getting better results, but like you mentioned, something is definitely still wrong. I’m still pretty convinced your nozzle is clogged, even though it’s new, and I’ll do my best to explain why!

To start, if your printer wasn’t working normally before you printed in wood, I’m totally wrong about everything below and you can stop reading here!

If your printer was working normally before you tried printing in wood though, that means the e-steps were already calibrated correctly, and they wouldn’t need to be re-calibrated after replacing the hot end. If you had replaced the extruder and it started acting this way, that would be a good reason to re-calibrate the e-steps, but replacing the hot-end shouldn’t have had an impact. After swapping an extruder, you calibrate e-steps to basically teach the printer how to extrude the correct amount of filament in the real world again since the new extruder might have different specs from the original and the printer has no way to know something has changed. A hot-end swap doesn’t necessitate recalibrating e-steps though because the extruder is the same and it’s still going to be pushing the same amount of filament through the printer.

If your nozzle is clogged and you recalibrate the e-steps, the measurements you take will be off since the printer can’t push filament through at the rate it should be able to. Your new benchy looks better than before, but that could be because the higher e-steps you calculated mean the printer is now forcing more filament past the blockage by working the extruder more. It’s been calibrated to compensate for the fact it can’t push filament through fast enough, but it’s working harder to do this and it will severely limit its speed before it starts underextruding again. I’m guessing this is the reason for the 3 hour long benchy at 20mm/s? You shouldn’t need to be at 220 C to get PLA to print at 20mm/s from a 0.4mm nozzle either.

Not all nozzles or hotends are well-made or handled with care at the factory. It’s totally possible you got one that shipped with some sort of tiny unnoticeable debris inside that worked its way down into the nozzle as the filament pushed it along. I have a cheap bag of 0.4mm nozzles that have metal shavings stuck in some of them and your first benchy is exactly what my prints look like when I use one of them. If possible, I still recommend changing the nozzle before doing anything more expensive like replacing the extruder. You’ll probably need to set the e-steps back to what they were before changing them though, otherwise you’ll be extruding too much filament if the new nozzle isn’t clogged and the old one is.