Why is the custom taxonomy archive page redirecting me to a single post? [closed]

Taxonomy archive index pages for custom taxonomies are not rendered using archive-{taxonomy}.php, but rather, using taxonomy-{taxonomy}-{term}.php, which falls back to taxonomy-{taxonomy}.php, which falls back to taxonomy.php. Refer to the Template Hierarchy.

WordPress interprets archive-{foobar}.php as archive-{post-type}.php, and would use that template to render the archive index for the foobar post-type. So, your artist taxonomy archive index page will never be rendered using archive-artist.php.

Try renaming the template file to taxonomy-artist.php.