I presume you did press the Apply button after you added the new shared folder(s). Sounds like a basic question/point, but it's easy to forget. Also, when you go back to the Library window to press the Refresh button. Keeping in mind if you're sharing a lot of files, LW can take a few mins to account for these new items. I'd suggest you do it one at a time. Go to the Tools-Options & Sharing & add a folder, press Apply & ok. Then go back to the Lib window & refresh it. See how it goes.

Oh also, don't forget that if your shared folders are several levels down, you'll need to click them open in the Lib window until u reach the bottom level & click onto that one before the files will appear to the right of it.

Since you're on pc which has the option of a mouse click that can 'unshare' folders. Make sure this has not played a part. I'm not a windows person so I don't know about that. (On a mac we only have one button.)