Hi. I thought I should offer a suggestion that you might want to consider doing a fix before you confirm that it is a bug of a forum software.
Why not create a new Bug Hunt forum and move all the threads to a new one and notice the effect? If you get the number of correct threads and posts, then this could solve the problem; thus you can delete that forum from the database.
But before you begin the procedure, you might want to take a forum offline before you test my "theory," one of 5 "scientific method."