Not scanning Custom Fields

Hello

I have used the following link for making the meta boxes
http://www.farinspace.com/how-to-create-custom-wordpress-meta-box/
What it is doing is… it is adding all the data of the custom fields as an array in the DB.

But when I am adding a broken link in the custom fields the plugin is not scanning the broken link.
Please advice

https://ww.wp.xz.cn/plugins/broken-link-checker/