Hmm, it looks like a Corner-only set, but keep in mind that when you change your current Mixed set to a Corner set, it won’t automatically erase the marked edges, and currently they will still be taken into account (see issue #3260). So, until that is fixed, either create a new set or first erase the edge labels, before changing your Terrain Set type to Corner.
If you’re still having issues even with a clean Corner setup, please show us again what you did.