Blender 2.82a bug? Some faces always shading flat even though all faces were set to shade smooth? This started happening randomly. I was in edit mode tinkering with the mesh and merging a few vertices. When I came out of edit mode I noticed the shading was messed up. No matter what I do, I can't seem to get the faces to shade smooth again.

Has anyone run into this problem? Here is the file:
I had something like this happen and it was double verts.

Removed them by selecting all verts and pressing Alt + M Merge > By Distance