Thanks. That is actually in line with my suspicions.
The 0.4mm nozzle has twice the flow of a 0.2mm nozzle for a given layer height.
So a fair comparison would be a .4 nozzle and a 0.03mm layer height.
From my own trials, that is doable with a .4 nozzle but borderline even with perfectly dry filament. And the .2 nozzles are more prone to heat creep anyway (although that is much more noticeable on the 2nd gen Bambu’s).
I’d recommend to dry the filament thoroughly before making another attempt while monitoring the environment/chamber temp. Stay well below 35°C (for PLA).
If that print fails though, you can consider going to an 0.08 min layer height or switching again to the .4mm nozzle with the Arachne wall generator and a 0.06mm layer height.
You could also increase flow by increasing speed but, well, that leads to a whole individual test matrix…
& 
PS: May be interest regarding low layer height printing