OK, I narrow down the problem a bit more. The user post multiple times in these monthly discussions. When the user searches by user (herself) and by the tag used in the discussion, the search result only returns the latest post by her in each of these monthly discussions.
Is there any way to return all the posts by her in each of these monthly discussions?
The 2nd and 3rd problems seem to have corrected itself over the period of a few days, oddly.