NOM

(JOSEPH DECLINES TO EXPLAIN THE BOOK OF MORMON TRANSLATION IN CONTEXT)
Br. Hyrum Smith said that he thought best that the information of the coming forth of the book of Mormon be related by Joseph himself to the Elders present that all might know for themselves.
Br. Joseph Smith jr. said that it was not intended to tell the world all the particulars of the coming forth of the book of Mormon, & also said that it was not expedient for him to relate these things &c.21
Br. Frederick G. Williams laid before the Conference the case of Sister Marsh & family who were somewhat destitute.22
Br. Titus Billings said that he was surprised that the case of Sister Marsh should be brought to this Conference, as she and her family were provided for as well as her brethren around her. (10/25/1831)

Joseph Smith Papers Historical note: To this point, JS apparently had not written a history of the production of the Book of Mormon. In April 1834, he provided “a relation of obtaining and translating the Book of Mormon” to a conference in Norton, Ohio, though the conference minutes do not provide any other information about what he said. An account was finally published in 1842, but it gave few details. (Minute Book 1, 21 Apr. 1834; JS, “Church History,” Times and Seasons, 1 Mar. 1842, 3:707; see also “The Histories of Joseph Smith, 1832–1844.”)

In other words, I haven't made that story up yet?

An apologist would likely say, "God told Joseph to take the Fifth."
But that is not not what Joseph Smith said. He essentially said, "I don't want to tell you, and I'm the prophet, the boss."
Which is a lot like what we hear today in some conference talks. Essentially, "we don't know the answer, and if God wants you to know the answer he will tell us."
Which makes it the skeptics problem, at least in their mind.
I think Linked is right, they just don't have a good answer yet.

He probably didn't want to talk about it any more because it was a failed financial exploit. I can't think of any instances of him teaching from it. The only thing I remember Joseph saying about the BoM in that time period was to scold members for not reading it.