Moving the global variable out of the loop works.
function recent_posts_grid() {
// Get latest posts
$custom_posts = get_posts( array( 'numberposts' => 6 ) );
// Remove post meta
beans_remove_action( 'beans_post_meta' );
// Add responsive grid
?><div id="recent-posts-grid" class="uk-grid uk-grid-match" data-uk-grid-margin=""><?php
// Global variable
global $post;
// Add posts
foreach ( $custom_posts as $post ) {
// Setup the postdata.
setup_postdata( $post );
?><div class="uk-width-large-1-3 uk-width-medium-1-2">
<article class="uk-article uk-panel-box"><?php
// Add post image and title
beans_post_image();
beans_post_title();
?></article></div><?php
}
?></div><?php
}