If you have been searching discussion posts lately and coming up with 0 results or only ones going back a few days, this is because there is a glitch in the system. Currently, only searches for posts going back to July 5th will work. The engineers are looking into it, however, so hopefully the problem will be resolved soon.
For more information, see this topic on the Goodreads Feedback group: https://www.goodreads.com/topic/show/...