yes, I agree, that was very unclear, and probably had an error or two. Only now had time to check up on this thread...
my issue was with a thin wall, i was trying to create a pocked for a magnet and use the thinnest wall possible.
below 0.4mm cura skipped it, didn't slice it. i think it was the same for 0.4mm.
then at 0.41mm... *pause to rerun tests with simple part*
ok, something is very wonky here.
see image link below. this part has a 0.41mm wall on the right, and 0.4 on the left (same for slats, but those i'll ignore right now). i tried values from 0.3 to 1.2, and at various stops eit