It happened to me as well. Two times, three different blue and one purple schematic that were already learned and used to make a piece of gear have gone missing from my craft window.
It is on a character that had three different skills before but I changed him into synthweaver. Now I can only gather.
I already sent a ticket but no response so far.
That may be the source of the bug. The first crafting skill I had worked flawlessly. When I changed it to a useful crafting skill, that's when everything broke.