Why does my face mesh look invisible in solid/material preview?

[shaili.dewangan (Shaili)]

I took face model fbx using polycam app.
And the preview in solid/material was coming fine.

I took one half of nose mesh and duplicated and joined on the other half after which it started to appear like this:

As you can see it looks fine on wire/render view. What could be wrong?

[anon23718311]

Check your face (polygons) orientation : After retopology, wired issue happened always
And you may also want to uncheck Backface Culling in the solid mode’s viewport shading options.