“Link Tweaks” Strike-through Not Consistent

I have removed much of the media linked on this page from the Media library. This resulted in many links getting a strike-through as expected, however not all the dead links were visually “tweaked.” So I ran the BLC “nuclear” option to recheck all links on the site, hoping it would catch the ones it missed. Now this page has lost all the dead link strike-throughs it had.

What causes a broken link to NOT get a strike-through, even when this option has been toggled in the Link Tweaks settings?

Thank you.

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