Joining 2 meshes, sharp shading problem

This is a head with a portion of it that is taken from another mesh by using Append and joined with the main one, also connecting the vertices one by one.

Can’t understand how to fix this shading issue.

Normals are all recalculated, there are no sharp edges, the topology is fine, there are no doubles, and also if I draw the normals of the faces and the vertices all is fine. All is set on smooth (on flat it gives the same issue too). But, if I flip the normals as “inside”, the problem disappears. But of course I want my normals outside…
No modifiers are applied here.

Is this in Material mode?

Sorry I’ve solved!
I was in Solid mode… Anyway It was because I had’t assigned any material to those portion! So easy…