The KOMAScript scrartcl documents class requires setting a special magic option to forget the factory defaults and use the main fonts everywhere.
\documentclass[
american,
paper=a4,
captions=tableheading,
headsepline=true,
footsepline=true,
draft=false,
overfullrule=false,
egregdoesnotlikesansseriftitles,% <------- magic
]{scrartcl}
Implemented in release 2023.1.12