Wrong topology or just UV viewport's artefact? Strange artefact in UV map view. Some "ghost" faces.

The faces that contain rounded cut are in the same plane. So I decided to leave N-gons because of flat plane.

The texture and MatCap looks good.





UPDATE

Finally I decided change topology to proper loop cuts. So UV map strange artefacts have gone.
Looks like some of your vertices are over-scaled on the Y (yellow).

It could also be from vertices that don't have an edge.

Try scaling down on the Y (yellow arrow below)