So I purchased eight rare All-out attack engravings from the market to progress to the epic books. Everything went through and I received them in my mailbox in-game. I attempt to use them all at once with the “use in bundle” resulting in using only one engraving in the stack of eight and the remaining 7 just vanished. I don’t know if this bug has been reported, but I advise everyone buying engravings off the market to use them individually instead of in a bundle. It may cost you quite the amount of gold.