Strange face appearance The below shading has me scratching my head.
The faces are coplanar, as far as I can tell.  It's not a normal issue.  The faces are attached (I can drag them around and everything stays attached.)  Also, I confirmed there is only one face present.
If I delete the faces and recreate them, the shading is corrected.
Thoughts?
This can happen with “custom split normal data” on the geometry. Go to the Properties tab and clear the custom split normals data. That should fix it.
This is technically a duplicate question.