Hi!
There is another similar issue with Custom Table and Post field with multiple choices:
If a post field saves data to a custom table, it also saves 'i:0;s:0:""' before other items.
I choose 2 posts and this is the data I have in the database
a:3:{i:0;s:0:"";i:1;i:194;i:2;i:197;}
Because of this, when I use this code
$post_ids = rwmb_meta( $field_id, ['storage_type' => 'custom_table', 'table' => $table_name] );
foreach ( $post_ids as $post_id ) {
echo '<p>', get_the_title( $post_id ), '</p>';
}
It shows as I have 3 posts, not 2.