Can't modify "Read More…" in functions.php

So my WordPress blog is only a small part of my personal site. As such, I create a script to output excerpts for the most recent posts on my home page. My custom Read More worked fine until I switched themes recently. Here’s what I have:

foreach ($postslist as $post) {
		setup_postdata($post);
		$excerpt = get_the_excerpt();
		?>
		<div class='blog-entry col-sm-4'>
			<a href="<?php the_permalink(); ?>">
				<h3><?php the_title(); ?></h3>
			</a>
			<div class='blog-entry-text'>
				<?php
					the_excerpt();
			    ?>
			</div>
			<div class='blog-entry-category'>
				<?php
					//echo the_category();
					outputCategories();
				?>
			</div>
		</div>
		<?php
	}

Relevant section of functions.php:

function custom_excerpt_length( $length ) {
	return 20;
}
add_filter( 'excerpt_length', 'custom_excerpt_length', 999 );

function new_excerpt_more( $more ) {
	return ' <a class="read-more" href="'. get_permalink( get_the_ID() ) . '">' . __('Read More', 'your-text-domain') . '</a>';
}
add_filter( 'excerpt_more', 'new_excerpt_more' );

Any help would be awesome!