Material not rendering on a particular face of the object

this is happening… there is a black patch on the object. I tried flipping normals, checked if the face is linked to the same material. everthing is proper, yet i have this problem… any idea why…
thank you.

Impossible to guess from an image. Share a file with material, lighting, camera, and some of the faces causing issues from that camera angle.

it is with the shader and the angle of the camera. cuz when i render from a different angle it is rendering…
i tried tweaking IOR it doesnt work
. the work is for a client. i can’t be sharing the scene…sorry… but i desperately need to know how to get rid of it.