Yep, there are some that don't work as a "link". It is usually caused by the person doing the post not understanding how to make it work.
No big deal for the reader to highlight the text by dragging the mouse arrow over the text with the left button held down, then type "Ctrl-C" to copy the text into the clipboard. Then open a new window or tab and paste the URL text into the address window by typing "Ctrl-V".
There IS help in the feedback forum for people to learn HOW to make the links clickable, but people have to know that the help exists and where to find it and have the inclination to actually look for it (which maybe I could do to list it here, but I am just not inclined to do it right now!)