horizontal line through link on web pages & blog posts

For some reason, certain links on nearly every page/post of my website have a horizontal line through them, as if they are non-functioning links. Yet they work just fine. There doesn’t seem to be any particular logic to which links are affected and it often changes each time I revisit a page/post. Any help/suggestions will be greatly appreciated.

The page I need help with: [log in to see the link]