Reply To: Subdivision modifier curving edge (2.80)
That’s an interesting screenshot but doesn’t seem to be the problem here, I think. I tried recalculating normals in the OP and tried manually flipping and resetting the normals for the few vertices around the problem corner once I saw your screenshot. But none of it seems to affect that edge in a good way.
Best I could get was straightening it out by flipping one whole face along that edge but that’s not really preferable:
