This should work. Just make sure that meta key is Project ID
.
function projects_posts() {
global $post;
$project_posts = get_posts( array(
'post__not_in' => array( $post->ID ),
'category_name' => 'team-resources',
'meta_key' => 'Project ID',
'meta_value' => get_post_meta( $post->ID, 'Project ID', 1 )
) );
$output="<ul>";
foreach ( $project_posts as $project_post ) {
$output .= '<li><a href="' . get_permalink( $project_post->ID ) . '">' .
apply_filters( 'the_title', $project_post->post_title, $project_post->ID ) .
'</a></li>';
}
$output .= '</ul>';
return $output;
}