Was working perfectly from whenever you added the favorites menu until 3.2. After 3.2 it is still there but doesn't function. I just deleted and reinstalled the lyrics link to confirm for myself that it's there, and now there is an added line below it, "(no recent documents)"
Meanwhile, over in the main menu "Lyrics" is now showing up under "Recent Documents" so that's a pretty convenient and a workable substitute for having a working link over in Favorites. (Before the latest update I had a file under "Recent Documents" called "Lyrics 4" which produced only an error ["... file not found"]. Was kind of mysterious because I never had any file called "Lyrics 4". Now that's gone and just "Lyrics" is there, linking to the Lyrics Reader, so far as I can tell.)
[Edit... oh funny, I just checked and every time I quit and start Pleco it adds a new file to the "Recent Documents" list... "Lyrics 12", then "Lyrics 13" etc etc... doesn't cause any problems, it's just there. No big deal. One way or another I can get to the Lyrics Reader by clicking "Reader" and then choosing "Lyrics Reader"... sorry this is so complicated for you. By the way, it's funny to me you keep noting that few people use this function. I for one in 10 years of using Pleco have never used the Web Reader. It seems too complicated. I usually just copy any web content and use the Clipboard Reader.]
thanks!