I suggest you to try to search for your projects using Notepad++. I am using version v5.9.3. In this version, if you go to Search --> Find in Files on the menu bar, a window will appear showing the options of your search. You can specify what to search, in which directory and of course if you want to search in all sub-folders and in hidden folders.
I believe this tool can help you find the VS Project that it is missing. Good luck!!
Thank you! Notepad++ works great.
I've found another tool with great search options and a funny name: Agent Ransack