Problem with h1 tags.

what theme are you using?

are you using a browser inspection tool to see where the h1 tags are?

can you post a link to your site to illustrate the problem?

the second <h1> tag is a screen reader tag:

<h1 class="screen-reader-text">Posts navigation</h1>

please post in your theme’s forum at https://wordpress.org/support/theme/awaken#postform to see if anybody there might be able to comment in your issue.

the code for ist is in /inc/template-tags.php;

if ( ! function_exists( 'awaken_paging_nav' ) ) :
/**
 * Display navigation to next/previous set of posts when applicable.
 */
function awaken_paging_nav() {
	// Don't print empty markup if there's only one page.
	if ( $GLOBALS['wp_query']->max_num_pages < 2 ) {
		return;
	}

	$paged        = get_query_var( 'paged' ) ? intval( get_query_var( 'paged' ) ) : 1;
	$pagenum_link = html_entity_decode( get_pagenum_link() );
	$query_args   = array();
	$url_parts    = explode( '?', $pagenum_link );

	if ( isset( $url_parts[1] ) ) {
		wp_parse_str( $url_parts[1], $query_args );
	}

	$pagenum_link = remove_query_arg( array_keys( $query_args ), $pagenum_link );
	$pagenum_link = trailingslashit( $pagenum_link ) . '%_%';

	$format  = $GLOBALS['wp_rewrite']->using_index_permalinks() && ! strpos( $pagenum_link, 'index.php' ) ? 'index.php/' : '';
	$format .= $GLOBALS['wp_rewrite']->using_permalinks() ? user_trailingslashit( 'page/%#%', 'paged' ) : '?paged=%#%';

	// Set up paginated links.
	$links = paginate_links( array(
		'base'     => $pagenum_link,
		'format'   => $format,
		'total'    => $GLOBALS['wp_query']->max_num_pages,
		'current'  => $paged,
		'mid_size' => 3,
		'add_args' => array_map( 'urlencode', $query_args ),
		'prev_text' => __( '<span class="meta-nav-prev"></span> Previous', 'awaken' ),
		'next_text' => __( 'Next <span class="meta-nav-next"></span>', 'awaken' ),
		'type'      => 'list',
	) );

	if ( $links ) :

	?>
	<nav class="navigation paging-navigation" role="navigation">
		<h1 class="screen-reader-text"><?php _e( 'Posts navigation', 'awaken' ); ?></h1>
			<?php echo $links; ?>
	</nav><!-- .navigation -->
	<?php
	endif;
}
endif;

as this function is pluggable, you can re-write it in your child theme.

please post in your theme’s forum at https://wordpress.org/support/theme/awaken#postform to see if anybody there might be able to comment further on your issue.