In the left side of the wireframe image it seems to be a not welded vertex or a degenerate quad, this can be the cause of the left side bump in the rendering.

In the right side I see nothing in the wireframe image, but it can be the same problem.

I also can see something similar more to the center of the wireframe, but in this case it produce no visible artifact in the rendering.

Check the mesh in detail to see if this problem do exist or are only my eyes

Stupidity also evolves!