Hi Dear Mary,
Yes, the other week I had received notice of two broken links on two different hubs. I went into the edit mode to find the pink highlighted links that were broken and everything looked fine. I went back again and checked and no highlighted area to indicate which link was broken. Then, out of the blue, I noticed the "Broken Links" button on my accounts/statistics page (as Kevin stated here), and when I clicked on it, it actually gave the specific links that were broken. So, there are actually broken links (people unpublished their hubs, in my case), but they will not be highlighted in your actual hub in edit mode for some reason now.
So great to see you back here this day.