Custom taxonomy pagination

Drop your custom query and go back to the default loop. Never replace the main query on the home page or any kind of archive page with a custom query. Use pre_get_posts to alter the main query variables before the main query runs

Your taxonomy archive page should look like this

if ( have_posts() ) {
    while ( have_posts() ) {
        the_post();

        // Your markup and template tags

    }
}